Merge pull request #2357 from keszybz/warnings-2

Remove gcc warnings v2

50 files changed, 263 insertions, 253 deletions

diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index b0fa079fec..a59459bc26 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -323,7 +323,7 @@ int main(int argc, char *argv[]) {
         errno = 0;
         device = udev_device_new_from_subsystem_sysname(udev, ss, sysname);
         if (!device) {
-                if (errno != 0)
+                if (errno > 0)
                         log_error_errno(errno, "Failed to get backlight or LED device '%s:%s': %m", ss, sysname);
                 else
                         log_oom();
diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
index acd48f6954..d07d1df5a8 100644
--- a/src/basic/btrfs-util.c
+++ b/src/basic/btrfs-util.c
@@ -2051,7 +2051,7 @@ int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret) {
 
                 args.key.nr_items = 256;
                 if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
-                        return -errno;
+                        return negative_errno();
 
                 if (args.key.nr_items <= 0)
                         break;
diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 3945d37c8d..f873fb89d3 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -93,7 +93,7 @@ int cg_read_pid(FILE *f, pid_t *_pid) {
                 if (feof(f))
                         return 0;
 
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
         }
 
         if (ul <= 0)
@@ -648,7 +648,7 @@ int cg_trim(const char *controller, const char *path, bool delete_root) {
         if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0) {
                 if (errno == ENOENT)
                         r = 0;
-                else if (errno != 0)
+                else if (errno > 0)
                         r = -errno;
                 else
                         r = -EIO;
@@ -2091,7 +2091,7 @@ int cg_kernel_controllers(Set *controllers) {
                         if (feof(f))
                                 break;
 
-                        if (ferror(f) && errno != 0)
+                        if (ferror(f) && errno > 0)
                                 return -errno;
 
                         return -EBADMSG;
diff --git a/src/basic/clock-util.c b/src/basic/clock-util.c
index 00f549c023..05788a360e 100644
--- a/src/basic/clock-util.c
+++ b/src/basic/clock-util.c
@@ -33,6 +33,7 @@
 #include "fd-util.h"
 #include "macro.h"
 #include "string-util.h"
+#include "util.h"
 
 int clock_get_hwclock(struct tm *tm) {
         _cleanup_close_ int fd = -1;
@@ -121,7 +122,8 @@ int clock_set_timezone(int *min) {
          * have read from the RTC.
          */
         if (settimeofday(tv_null, &tz) < 0)
-                return -errno;
+                return negative_errno();
+
         if (min)
                 *min = minutesdelta;
         return 0;
diff --git a/src/basic/errno-list.c b/src/basic/errno-list.c
index 0a66902ac9..b4d080103b 100644
--- a/src/basic/errno-list.c
+++ b/src/basic/errno-list.c
@@ -25,7 +25,7 @@
 #include "macro.h"
 
 static const struct errno_name* lookup_errno(register const char *str,
-                                                 register unsigned int len);
+                                             register unsigned int len);
 
 #include "errno-from-name.h"
 #include "errno-to-name.h"
@@ -48,8 +48,9 @@ int errno_from_name(const char *name) {
 
         sc = lookup_errno(name, strlen(name));
         if (!sc)
-                return 0;
+                return -EINVAL;
 
+        assert(sc->id > 0);
         return sc->id;
 }
 
diff --git a/src/basic/escape.c b/src/basic/escape.c
index ab282efa3c..5661f36813 100644
--- a/src/basic/escape.c
+++ b/src/basic/escape.c
@@ -119,16 +119,18 @@ char *cescape(const char *s) {
         return cescape_length(s, strlen(s));
 }
 
-int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode) {
+int cunescape_one(const char *p, size_t length, uint32_t *ret, bool *eight_bit) {
         int r = 1;
 
         assert(p);
         assert(*p);
         assert(ret);
 
-        /* Unescapes C style. Returns the unescaped character in ret,
-         * unless we encountered a \u sequence in which case the full
-         * unicode character is returned in ret_unicode, instead. */
+        /* Unescapes C style. Returns the unescaped character in ret.
+         * Sets *eight_bit to true if the escaped sequence either fits in
+         * one byte in UTF-8 or is a non-unicode literal byte and should
+         * instead be copied directly.
+         */
 
         if (length != (size_t) -1 && length < 1)
                 return -EINVAL;
@@ -190,7 +192,8 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode
                 if (a == 0 && b == 0)
                         return -EINVAL;
 
-                *ret = (char) ((a << 4U) | b);
+                *ret = (a << 4U) | b;
+                *eight_bit = true;
                 r = 3;
                 break;
         }
@@ -217,16 +220,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode
                 if (c == 0)
                         return -EINVAL;
 
-                if (c < 128)
-                        *ret = c;
-                else {
-                        if (!ret_unicode)
-                                return -EINVAL;
-
-                        *ret = 0;
-                        *ret_unicode = c;
-                }
-
+                *ret = c;
                 r = 5;
                 break;
         }
@@ -258,16 +252,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode
                 if (!unichar_is_valid(c))
                         return -EINVAL;
 
-                if (c < 128)
-                        *ret = c;
-                else {
-                        if (!ret_unicode)
-                                return -EINVAL;
-
-                        *ret = 0;
-                        *ret_unicode = c;
-                }
-
+                *ret = c;
                 r = 9;
                 break;
         }
@@ -309,6 +294,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode
                         return -EINVAL;
 
                 *ret = m;
+                *eight_bit = true;
                 r = 3;
                 break;
         }
@@ -342,7 +328,7 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi
         for (f = s, t = r + pl; f < s + length; f++) {
                 size_t remaining;
                 uint32_t u;
-                char c;
+                bool eight_bit = false;
                 int k;
 
                 remaining = s + length - f;
@@ -365,7 +351,7 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi
                         return -EINVAL;
                 }
 
-                k = cunescape_one(f + 1, remaining - 1, &c, &u);
+                k = cunescape_one(f + 1, remaining - 1, &u, &eight_bit);
                 if (k < 0) {
                         if (flags & UNESCAPE_RELAX) {
                                 /* Invalid escape code, let's take it literal then */
@@ -377,14 +363,13 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi
                         return k;
                 }
 
-                if (c != 0)
-                        /* Non-Unicode? Let's encode this directly */
-                        *(t++) = c;
+                f += k;
+                if (eight_bit)
+                        /* One byte? Set directly as specified */
+                        *(t++) = u;
                 else
-                        /* Unicode? Then let's encode this in UTF-8 */
+                        /* Otherwise encode as multi-byte UTF-8 */
                         t += utf8_encode_unichar(t, u);
-
-                f += k;
         }
 
         *t = 0;
diff --git a/src/basic/escape.h b/src/basic/escape.h
index c710f01743..d943aa71f5 100644
--- a/src/basic/escape.h
+++ b/src/basic/escape.h
@@ -45,7 +45,7 @@ size_t cescape_char(char c, char *buf);
 int cunescape(const char *s, UnescapeFlags flags, char **ret);
 int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret);
 int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret);
-int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode);
+int cunescape_one(const char *p, size_t length, uint32_t *ret, bool *eight_bit);
 
 char *xescape(const char *s, const char *bad);
 
diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c
index 7cc2a1de13..090d2a7884 100644
--- a/src/basic/extract-word.c
+++ b/src/basic/extract-word.c
@@ -108,8 +108,9 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra
 
                         if (flags & EXTRACT_CUNESCAPE) {
                                 uint32_t u;
+                                bool eight_bit = false;
 
-                                r = cunescape_one(*p, (size_t) -1, &c, &u);
+                                r = cunescape_one(*p, (size_t) -1, &u, &eight_bit);
                                 if (r < 0) {
                                         if (flags & EXTRACT_CUNESCAPE_RELAX) {
                                                 s[sz++] = '\\';
@@ -119,10 +120,10 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra
                                 } else {
                                         (*p) += r - 1;
 
-                                        if (c != 0)
-                                                s[sz++] = c; /* normal explicit char */
+                                        if (eight_bit)
+                                                s[sz++] = u;
                                         else
-                                                sz += utf8_encode_unichar(s + sz, u); /* unicode chars we'll encode as utf8 */
+                                                sz += utf8_encode_unichar(s + sz, u);
                                 }
                         } else
                                 s[sz++] = c;
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 3a237252b5..5ed5460904 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -165,7 +165,7 @@ int read_one_line_file(const char *fn, char **line) {
         if (!fgets(t, sizeof(t), f)) {
 
                 if (ferror(f))
-                        return errno ? -errno : -EIO;
+                        return errno > 0 ? -errno : -EIO;
 
                 t[0] = 0;
         }
@@ -1064,7 +1064,7 @@ int fflush_and_check(FILE *f) {
         fflush(f);
 
         if (ferror(f))
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return 0;
 }
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index fb760abe18..d31bd6e273 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -481,7 +481,7 @@ int get_files_in_directory(const char *path, char ***list) {
 
                 errno = 0;
                 de = readdir(d);
-                if (!de && errno != 0)
+                if (!de && errno > 0)
                         return -errno;
                 if (!de)
                         break;
diff --git a/src/basic/glob-util.c b/src/basic/glob-util.c
index a0be0efd40..811ab6ec36 100644
--- a/src/basic/glob-util.c
+++ b/src/basic/glob-util.c
@@ -40,7 +40,7 @@ int glob_exists(const char *path) {
         if (k == GLOB_NOSPACE)
                 return -ENOMEM;
         if (k != 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return !strv_isempty(g.gl_pathv);
 }
@@ -58,7 +58,7 @@ int glob_extend(char ***strv, const char *path) {
         if (k == GLOB_NOSPACE)
                 return -ENOMEM;
         if (k != 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
         if (strv_isempty(g.gl_pathv))
                 return -ENOENT;
 
diff --git a/src/basic/in-addr-util.c b/src/basic/in-addr-util.c
index 5143dddf8f..8609ffb3c9 100644
--- a/src/basic/in-addr-util.c
+++ b/src/basic/in-addr-util.c
@@ -219,7 +219,7 @@ int in_addr_to_string(int family, const union in_addr_union *u, char **ret) {
         errno = 0;
         if (!inet_ntop(family, u, x, l)) {
                 free(x);
-                return errno ? -errno : -EINVAL;
+                return errno > 0 ? -errno : -EINVAL;
         }
 
         *ret = x;
@@ -236,7 +236,7 @@ int in_addr_from_string(int family, const char *s, union in_addr_union *ret) {
 
         errno = 0;
         if (inet_pton(family, s, ret) <= 0)
-                return errno ? -errno : -EINVAL;
+                return errno > 0 ? -errno : -EINVAL;
 
         return 0;
 }
diff --git a/src/basic/parse-util.c b/src/basic/parse-util.c
index 618ef5d564..d8de6f90ea 100644
--- a/src/basic/parse-util.c
+++ b/src/basic/parse-util.c
@@ -81,7 +81,7 @@ int parse_mode(const char *s, mode_t *ret) {
 
         errno = 0;
         l = strtol(s, &x, 8);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -176,7 +176,7 @@ int parse_size(const char *t, uint64_t base, uint64_t *size) {
 
                 errno = 0;
                 l = strtoull(p, &e, 10);
-                if (errno != 0)
+                if (errno > 0)
                         return -errno;
                 if (e == p)
                         return -EINVAL;
@@ -192,7 +192,7 @@ int parse_size(const char *t, uint64_t base, uint64_t *size) {
                                 char *e2;
 
                                 l2 = strtoull(e, &e2, 10);
-                                if (errno != 0)
+                                if (errno > 0)
                                         return -errno;
 
                                 /* Ignore failure. E.g. 10.M is valid */
@@ -330,7 +330,7 @@ int safe_atou(const char *s, unsigned *ret_u) {
 
         errno = 0;
         l = strtoul(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -352,7 +352,7 @@ int safe_atoi(const char *s, int *ret_i) {
 
         errno = 0;
         l = strtol(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -374,7 +374,7 @@ int safe_atollu(const char *s, long long unsigned *ret_llu) {
 
         errno = 0;
         l = strtoull(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -394,7 +394,7 @@ int safe_atolli(const char *s, long long int *ret_lli) {
 
         errno = 0;
         l = strtoll(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -414,7 +414,7 @@ int safe_atou8(const char *s, uint8_t *ret) {
 
         errno = 0;
         l = strtoul(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -438,7 +438,7 @@ int safe_atou16(const char *s, uint16_t *ret) {
 
         errno = 0;
         l = strtoul(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -460,7 +460,7 @@ int safe_atoi16(const char *s, int16_t *ret) {
 
         errno = 0;
         l = strtol(s, &x, 0);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
         if (!x || x == s || *x)
                 return -EINVAL;
@@ -485,7 +485,7 @@ int safe_atod(const char *s, double *ret_d) {
 
         errno = 0;
         d = strtod_l(s, &x, loc);
-        if (errno != 0) {
+        if (errno > 0) {
                 freelocale(loc);
                 return -errno;
         }
diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 61fab0e087..4837bb2d7d 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -102,7 +102,7 @@ int path_make_absolute_cwd(const char *p, char **ret) {
 
                 cwd = get_current_dir_name();
                 if (!cwd)
-                        return -errno;
+                        return negative_errno();
 
                 c = strjoin(cwd, "/", p, NULL);
         }
diff --git a/src/basic/rm-rf.c b/src/basic/rm-rf.c
index 14f8474da0..4807561723 100644
--- a/src/basic/rm-rf.c
+++ b/src/basic/rm-rf.c
@@ -82,7 +82,7 @@ int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) {
                 errno = 0;
                 de = readdir(d);
                 if (!de) {
-                        if (errno != 0 && ret == 0)
+                        if (errno > 0 && ret == 0)
                                 ret = -errno;
                         return ret;
                 }
diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index a39764472b..7c9de72bb7 100644
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -128,7 +128,7 @@ int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
 
         errno = 0;
         if (!fgets(line, sizeof(line), f))
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         truncate_nl(line);
 
@@ -212,7 +212,7 @@ int ask_string(char **ret, const char *text, ...) {
 
                 errno = 0;
                 if (!fgets(line, sizeof(line), stdin))
-                        return errno ? -errno : -EIO;
+                        return errno > 0 ? -errno : -EIO;
 
                 if (!endswith(line, "\n"))
                         putchar('\n');
diff --git a/src/basic/user-util.c b/src/basic/user-util.c
index 56e1a3be48..70a6e1f5e4 100644
--- a/src/basic/user-util.c
+++ b/src/basic/user-util.c
@@ -68,7 +68,7 @@ int parse_uid(const char *s, uid_t *ret) {
         if (!uid_is_valid(uid))
                 return -ENXIO; /* we return ENXIO instead of EINVAL
                                 * here, to make it easy to distuingish
-                                * invalid numeric uids invalid
+                                * invalid numeric uids from invalid
                                 * strings. */
 
         if (ret)
diff --git a/src/basic/util.c b/src/basic/util.c
index 9e0b576283..4434ecfdf6 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -513,7 +513,7 @@ int on_ac_power(void) {
 
                 errno = 0;
                 de = readdir(d);
-                if (!de && errno != 0)
+                if (!de && errno > 0)
                         return -errno;
 
                 if (!de)
diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index c2238c8c43..eae0808f9e 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -141,7 +141,7 @@ static int property_get_nice(
         else {
                 errno = 0;
                 n = getpriority(PRIO_PROCESS, 0);
-                if (errno != 0)
+                if (errno > 0)
                         n = 0;
         }
 
@@ -1382,7 +1382,7 @@ int bus_exec_context_set_transient_property(
                                 dirs = &c->read_write_dirs;
                         else if (streq(name, "ReadOnlyDirectories"))
                                 dirs = &c->read_only_dirs;
-                        else if (streq(name, "InaccessibleDirectories"))
+                        else /* "InaccessibleDirectories" */
                                 dirs = &c->inaccessible_dirs;
 
                         if (strv_length(l) == 0) {
diff --git a/src/core/execute.c b/src/core/execute.c
index ac91568b63..0028730889 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -2319,7 +2319,7 @@ int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l) {
                                 continue;
 
                         strv_free(r);
-                        return errno ? -errno : -EINVAL;
+                        return errno > 0 ? -errno : -EINVAL;
                 }
                 count = pglob.gl_pathc;
                 if (count == 0) {
@@ -2683,7 +2683,7 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
                 fputc('\n', f);
         }
 
-        if (c->syscall_errno != 0)
+        if (c->syscall_errno > 0)
                 fprintf(f,
                         "%sSystemCallErrorNumber: %s\n",
                         prefix, strna(errno_to_name(c->syscall_errno)));
diff --git a/src/core/manager.c b/src/core/manager.c
index 39e3cbbfe1..a83a8b013a 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -233,7 +233,7 @@ static int have_ask_password(void) {
 
                 errno = 0;
                 de = readdir(dir);
-                if (!de && errno != 0)
+                if (!de && errno > 0)
                         return -errno;
                 if (!de)
                         return false;
diff --git a/src/firstboot/firstboot.c b/src/firstboot/firstboot.c
index 469ee7af68..cc5e9741fe 100644
--- a/src/firstboot/firstboot.c
+++ b/src/firstboot/firstboot.c
@@ -502,7 +502,7 @@ static int write_root_shadow(const char *path, const struct spwd *p) {
 
         errno = 0;
         if (putspent(p, f) != 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return fflush_and_check(f);
 }
diff --git a/src/getty-generator/getty-generator.c b/src/getty-generator/getty-generator.c
index 03df7365b5..bddc0c441a 100644
--- a/src/getty-generator/getty-generator.c
+++ b/src/getty-generator/getty-generator.c
@@ -112,7 +112,7 @@ static int verify_tty(const char *name) {
 
         errno = 0;
         if (isatty(fd) <= 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return 0;
 }
diff --git a/src/import/aufs-util.c b/src/import/aufs-util.c
index 82f519958c..b44dbb14ea 100644
--- a/src/import/aufs-util.c
+++ b/src/import/aufs-util.c
@@ -69,7 +69,7 @@ int aufs_resolve(const char *path) {
         errno = 0;
         r = nftw(path, nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
         if (r == FTW_STOP)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return 0;
 }
diff --git a/src/journal-remote/journal-gatewayd.c b/src/journal-remote/journal-gatewayd.c
index 4e96fb0a4d..7120a08e50 100644
--- a/src/journal-remote/journal-gatewayd.c
+++ b/src/journal-remote/journal-gatewayd.c
@@ -700,7 +700,7 @@ static int request_handler_file(
         if (fstat(fd, &st) < 0)
                 return mhd_respondf(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to stat file: %m\n");
 
-        response = MHD_create_response_from_fd_at_offset(st.st_size, fd, 0);
+        response = MHD_create_response_from_fd_at_offset64(st.st_size, fd, MHD_VERSION);
         if (!response)
                 return respond_oom(connection);
 
@@ -840,7 +840,7 @@ static int request_handler(
         assert(method);
 
         if (!streq(method, "GET"))
-                return mhd_respond(connection, MHD_HTTP_METHOD_NOT_ACCEPTABLE,
+                return mhd_respond(connection, MHD_HTTP_NOT_ACCEPTABLE,
                                    "Unsupported method.\n");
 
 
diff --git a/src/journal-remote/journal-remote.c b/src/journal-remote/journal-remote.c
index 3f93e85232..2126606661 100644
--- a/src/journal-remote/journal-remote.c
+++ b/src/journal-remote/journal-remote.c
@@ -587,7 +587,7 @@ static int request_handler(
                                            *connection_cls);
 
         if (!streq(method, "POST"))
-                return mhd_respond(connection, MHD_HTTP_METHOD_NOT_ACCEPTABLE,
+                return mhd_respond(connection, MHD_HTTP_NOT_ACCEPTABLE,
                                    "Unsupported method.\n");
 
         if (!streq(url, "/upload"))
diff --git a/src/journal-remote/microhttpd-util.h b/src/journal-remote/microhttpd-util.h
index 3e8c4fa6d1..cba57403a3 100644
--- a/src/journal-remote/microhttpd-util.h
+++ b/src/journal-remote/microhttpd-util.h
@@ -26,6 +26,15 @@
 
 #include "macro.h"
 
+/* Compatiblity with libmicrohttpd < 0.9.38 */
+#ifndef MHD_HTTP_NOT_ACCEPTABLE
+#define MHD_HTTP_NOT_ACCEPTABLE MHD_HTTP_METHOD_NOT_ACCEPTABLE
+#endif
+
+#if MHD_VERSION < 0x00094203
+#define MHD_create_response_from_fd_at_offset64 MHD_create_response_from_fd_at_offset
+#endif
+
 void microhttpd_logger(void *arg, const char *fmt, va_list ap) _printf_(2, 0);
 
 /* respond_oom() must be usable with return, hence this form. */
diff --git a/src/journal/coredump.c b/src/journal/coredump.c
index f750ddfcbd..869c8fea03 100644
--- a/src/journal/coredump.c
+++ b/src/journal/coredump.c
@@ -527,7 +527,7 @@ static int compose_open_fds(pid_t pid, char **open_fds) {
         errno = 0;
         stream = safe_fclose(stream);
 
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
 
         *open_fds = buffer;
diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index a8a9b72080..cfcc2c4302 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -1330,7 +1330,7 @@ static int server_parse_proc_cmdline(Server *s) {
 
         p = line;
         for(;;) {
-                _cleanup_free_ char *word;
+                _cleanup_free_ char *word = NULL;
 
                 r = extract_first_word(&p, &word, NULL, 0);
                 if (r < 0)
diff --git a/src/libsystemd-network/sd-ndisc.c b/src/libsystemd-network/sd-ndisc.c
index d8154f0587..0ee466b32a 100644
--- a/src/libsystemd-network/sd-ndisc.c
+++ b/src/libsystemd-network/sd-ndisc.c
@@ -1,3 +1,5 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
 /***
   This file is part of systemd.
 
@@ -112,7 +114,7 @@ static NDiscPrefix *ndisc_prefix_unref(NDiscPrefix *prefix) {
 }
 
 static int ndisc_prefix_new(sd_ndisc *nd, NDiscPrefix **ret) {
-        _cleanup_free_ NDiscPrefix *prefix = NULL;
+        NDiscPrefix *prefix;
 
         assert(ret);
 
@@ -125,8 +127,6 @@ static int ndisc_prefix_new(sd_ndisc *nd, NDiscPrefix **ret) {
         prefix->nd = nd;
 
         *ret = prefix;
-        prefix = NULL;
-
         return 0;
 }
 
@@ -314,7 +314,6 @@ static int ndisc_prefix_match(sd_ndisc *nd, const struct in6_addr *addr,
         LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) {
                 if (prefix->valid_until < time_now) {
                         prefix = ndisc_prefix_unref(prefix);
-
                         continue;
                 }
 
@@ -355,14 +354,13 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len,
 
         r = ndisc_prefix_match(nd, &prefix_opt->nd_opt_pi_prefix,
                                prefix_opt->nd_opt_pi_prefix_len, &prefix);
+        if (r < 0) {
+                if (r != -EADDRNOTAVAIL)
+                        return r;
 
-        if (r < 0 && r != -EADDRNOTAVAIL)
-                return r;
-
-        /* if router advertisment prefix valid timeout is zero, the timeout
-           callback will be called immediately to clean up the prefix */
+                /* if router advertisment prefix valid timeout is zero, the timeout
+                   callback will be called immediately to clean up the prefix */
 
-        if (r == -EADDRNOTAVAIL) {
                 r = ndisc_prefix_new(nd, &prefix);
                 if (r < 0)
                         return r;
@@ -373,9 +371,9 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len,
                         sizeof(prefix->addr));
 
                 log_ndisc(nd, "New prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
-                             SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
-                             prefix->len, lifetime_valid,
-                             format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC));
+                          SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
+                          prefix->len, lifetime_valid,
+                          format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC));
 
                 LIST_PREPEND(prefixes, nd->prefixes, prefix);
 
@@ -386,17 +384,17 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len,
                         prefixlen = MIN(prefix->len, prefix_opt->nd_opt_pi_prefix_len);
 
                         log_ndisc(nd, "Prefix length mismatch %d/%d using %d",
-                                     prefix->len,
-                                     prefix_opt->nd_opt_pi_prefix_len,
-                                     prefixlen);
+                                  prefix->len,
+                                  prefix_opt->nd_opt_pi_prefix_len,
+                                  prefixlen);
 
                         prefix->len = prefixlen;
                 }
 
                 log_ndisc(nd, "Update prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
-                             SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
-                             prefix->len, lifetime_valid,
-                             format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC));
+                          SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
+                          prefix->len, lifetime_valid,
+                          format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC));
         }
 
         r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
@@ -450,7 +448,7 @@ static int ndisc_ra_parse(sd_ndisc *nd, struct nd_router_advert *ra, ssize_t len
                                 nd->mtu = MAX(mtu, IP6_MIN_MTU);
 
                                 log_ndisc(nd, "Router Advertisement link MTU %d using %d",
-                                             mtu, nd->mtu);
+                                          mtu, nd->mtu);
                         }
 
                         break;
diff --git a/src/libsystemd/sd-bus/bus-error.c b/src/libsystemd/sd-bus/bus-error.c
index 404eaa3c89..c77eb5fd03 100644
--- a/src/libsystemd/sd-bus/bus-error.c
+++ b/src/libsystemd/sd-bus/bus-error.c
@@ -93,14 +93,14 @@ static int bus_error_name_to_errno(const char *name) {
         p = startswith(name, "System.Error.");
         if (p) {
                 r = errno_from_name(p);
-                if (r <= 0)
+                if (r < 0)
                         return EIO;
 
                 return r;
         }
 
-        if (additional_error_maps) {
-                for (map = additional_error_maps; *map; map++) {
+        if (additional_error_maps)
+                for (map = additional_error_maps; *map; map++)
                         for (m = *map;; m++) {
                                 /* For additional error maps the end marker is actually the end marker */
                                 if (m->code == BUS_ERROR_MAP_END_MARKER)
@@ -109,15 +109,13 @@ static int bus_error_name_to_errno(const char *name) {
                                 if (streq(m->name, name))
                                         return m->code;
                         }
-                }
-        }
 
         m = __start_BUS_ERROR_MAP;
         while (m < __stop_BUS_ERROR_MAP) {
                 /* For magic ELF error maps, the end marker might
                  * appear in the middle of things, since multiple maps
                  * might appear in the same section. Hence, let's skip
-                 * over it, but realign the pointer to the netx 8byte
+                 * over it, but realign the pointer to the next 8 byte
                  * boundary, which is the selected alignment for the
                  * arrays. */
                 if (m->code == BUS_ERROR_MAP_END_MARKER) {
@@ -258,25 +256,24 @@ int bus_error_setfv(sd_bus_error *e, const char *name, const char *format, va_li
 
         if (!name)
                 return 0;
-        if (!e)
-                goto finish;
 
-        assert_return(!bus_error_is_dirty(e), -EINVAL);
+        if (e) {
+                assert_return(!bus_error_is_dirty(e), -EINVAL);
 
-        e->name = strdup(name);
-        if (!e->name) {
-                *e = BUS_ERROR_OOM;
-                return -ENOMEM;
-        }
+                e->name = strdup(name);
+                if (!e->name) {
+                        *e = BUS_ERROR_OOM;
+                        return -ENOMEM;
+                }
 
-        /* If we hit OOM on formatting the pretty message, we ignore
-         * this, since we at least managed to write the error name */
-        if (format)
-                (void) vasprintf((char**) &e->message, format, ap);
+                /* If we hit OOM on formatting the pretty message, we ignore
+                 * this, since we at least managed to write the error name */
+                if (format)
+                        (void) vasprintf((char**) &e->message, format, ap);
 
-        e->_need_free = 1;
+                e->_need_free = 1;
+        }
 
-finish:
         return -bus_error_name_to_errno(name);
 }
 
@@ -582,27 +579,29 @@ const char *bus_error_message(const sd_bus_error *e, int error) {
         return strerror(error);
 }
 
+static bool map_ok(const sd_bus_error_map *map) {
+        for (; map->code != BUS_ERROR_MAP_END_MARKER; map++)
+                if (!map->name || map->code <=0)
+                        return false;
+        return true;
+}
+
 _public_ int sd_bus_error_add_map(const sd_bus_error_map *map) {
         const sd_bus_error_map **maps = NULL;
         unsigned n = 0;
 
         assert_return(map, -EINVAL);
+        assert_return(map_ok(map), -EINVAL);
 
-        if (additional_error_maps) {
-                for (;; n++) {
-                        if (additional_error_maps[n] == NULL)
-                                break;
-
+        if (additional_error_maps)
+                for (; additional_error_maps[n] != NULL; n++)
                         if (additional_error_maps[n] == map)
                                 return 0;
-                }
-        }
 
         maps = realloc_multiply(additional_error_maps, sizeof(struct sd_bus_error_map*), n + 2);
         if (!maps)
                 return -ENOMEM;
 
-
         maps[n] = map;
         maps[n+1] = NULL;
 
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index b2d685855e..e7d6170eec 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -270,8 +270,8 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         struct bus_body_part *part;
         struct kdbus_item *d;
         const char *destination;
-        bool well_known;
-        uint64_t unique;
+        bool well_known = false;
+        uint64_t dst_id;
         size_t sz, dl;
         unsigned i;
         int r;
@@ -288,13 +288,21 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         destination = m->destination ?: m->destination_ptr;
 
         if (destination) {
-                r = bus_kernel_parse_unique_name(destination, &unique);
+                r = bus_kernel_parse_unique_name(destination, &dst_id);
                 if (r < 0)
                         return r;
-
-                well_known = r == 0;
+                if (r == 0) {
+                        well_known = true;
+
+                        /* verify_destination_id will usually be 0, which makes the kernel
+                         * driver only look at the provided well-known name. Otherwise,
+                         * the kernel will make sure the provided destination id matches
+                         * the owner of the provided well-known-name, and fail if they
+                         * differ. Currently, this is only needed for bus-proxyd. */
+                        dst_id = m->verify_destination_id;
+                }
         } else
-                well_known = false;
+                dst_id = KDBUS_DST_ID_BROADCAST;
 
         sz = offsetof(struct kdbus_msg, items);
 
@@ -332,15 +340,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
                 ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_NO_AUTO_START : 0) |
                 ((m->header->type == SD_BUS_MESSAGE_SIGNAL) ? KDBUS_MSG_SIGNAL : 0);
 
-        if (well_known)
-                /* verify_destination_id will usually be 0, which makes the kernel driver only look
-                 * at the provided well-known name. Otherwise, the kernel will make sure the provided
-                 * destination id matches the owner of the provided weel-known-name, and fail if they
-                 * differ. Currently, this is only needed for bus-proxyd. */
-                m->kdbus->dst_id = m->verify_destination_id;
-        else
-                m->kdbus->dst_id = destination ? unique : KDBUS_DST_ID_BROADCAST;
-
+        m->kdbus->dst_id = dst_id;
         m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
         m->kdbus->cookie = m->header->dbus2.cookie;
         m->kdbus->priority = m->priority;
diff --git a/src/libsystemd/sd-bus/test-bus-error.c b/src/libsystemd/sd-bus/test-bus-error.c
index c52405463e..407fd14555 100644
--- a/src/libsystemd/sd-bus/test-bus-error.c
+++ b/src/libsystemd/sd-bus/test-bus-error.c
@@ -44,7 +44,15 @@ static void test_error(void) {
         assert_se(sd_bus_error_is_set(&error));
         sd_bus_error_free(&error);
 
+        /* Check with no error */
         assert_se(!sd_bus_error_is_set(&error));
+        assert_se(sd_bus_error_setf(&error, NULL, "yyy %i", -1) == 0);
+        assert_se(error.name == NULL);
+        assert_se(error.message == NULL);
+        assert_se(!sd_bus_error_has_name(&error, SD_BUS_ERROR_FILE_NOT_FOUND));
+        assert_se(sd_bus_error_get_errno(&error) == 0);
+        assert_se(!sd_bus_error_is_set(&error));
+
         assert_se(sd_bus_error_setf(&error, SD_BUS_ERROR_FILE_NOT_FOUND, "yyy %i", -1) == -ENOENT);
         assert_se(streq(error.name, SD_BUS_ERROR_FILE_NOT_FOUND));
         assert_se(streq(error.message, "yyy -1"));
@@ -112,6 +120,16 @@ static void test_error(void) {
         assert_se(sd_bus_error_has_name(&error, SD_BUS_ERROR_IO_ERROR));
         assert_se(sd_bus_error_get_errno(&error) == EIO);
         assert_se(sd_bus_error_is_set(&error));
+        sd_bus_error_free(&error);
+
+        /* Check with no error */
+        assert_se(!sd_bus_error_is_set(&error));
+        assert_se(sd_bus_error_set_errnof(&error, 0, "Waldi %c", 'X') == 0);
+        assert_se(error.name == NULL);
+        assert_se(error.message == NULL);
+        assert_se(!sd_bus_error_has_name(&error, SD_BUS_ERROR_IO_ERROR));
+        assert_se(sd_bus_error_get_errno(&error) == 0);
+        assert_se(!sd_bus_error_is_set(&error));
 }
 
 extern const sd_bus_error_map __start_BUS_ERROR_MAP[];
@@ -167,6 +185,16 @@ static const sd_bus_error_map test_errors4[] = {
         SD_BUS_ERROR_MAP_END
 };
 
+static const sd_bus_error_map test_errors_bad1[] = {
+        SD_BUS_ERROR_MAP("org.freedesktop.custom-dbus-error-1", 0),
+        SD_BUS_ERROR_MAP_END
+};
+
+static const sd_bus_error_map test_errors_bad2[] = {
+        SD_BUS_ERROR_MAP("org.freedesktop.custom-dbus-error-1", -1),
+        SD_BUS_ERROR_MAP_END
+};
+
 static void test_errno_mapping_custom(void) {
         assert_se(sd_bus_error_set(NULL, "org.freedesktop.custom-dbus-error", NULL) == -5);
         assert_se(sd_bus_error_set(NULL, "org.freedesktop.custom-dbus-error-2", NULL) == -52);
@@ -190,6 +218,9 @@ static void test_errno_mapping_custom(void) {
         assert_se(sd_bus_error_set(NULL, "org.freedesktop.custom-dbus-error-y", NULL) == -EIO);
 
         assert_se(sd_bus_error_set(NULL, BUS_ERROR_NO_SUCH_UNIT, NULL) == -ENOENT);
+
+        assert_se(sd_bus_error_add_map(test_errors_bad1) == -EINVAL);
+        assert_se(sd_bus_error_add_map(test_errors_bad2) == -EINVAL);
 }
 
 int main(int argc, char *argv[]) {
diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index f44054a7b5..9633e46ce0 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -494,7 +494,7 @@ static int handle_uevent_line(sd_device *device, const char *key, const char *va
 
 int device_read_uevent_file(sd_device *device) {
         _cleanup_free_ char *uevent = NULL;
-        const char *syspath, *key, *value, *major = NULL, *minor = NULL;
+        const char *syspath, *key = NULL, *value = NULL, *major = NULL, *minor = NULL;
         char *path;
         size_t uevent_len;
         unsigned i;
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index aeb06ad9a8..11c7330b9b 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -661,8 +661,10 @@ static int event_make_signal_data(
                 d->priority = priority;
 
                 r = hashmap_put(e->signal_data, &d->priority, d);
-                if (r < 0)
+                if (r < 0) {
+                        free(d);
                         return r;
+                }
 
                 added = true;
         }
@@ -2751,6 +2753,12 @@ _public_ int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec) {
         assert_return(e, -EINVAL);
         assert_return(usec, -EINVAL);
         assert_return(!event_pid_changed(e), -ECHILD);
+        assert_return(IN_SET(clock,
+                             CLOCK_REALTIME,
+                             CLOCK_REALTIME_ALARM,
+                             CLOCK_MONOTONIC,
+                             CLOCK_BOOTTIME,
+                             CLOCK_BOOTTIME_ALARM), -EOPNOTSUPP);
 
         if (!dual_timestamp_is_set(&e->timestamp)) {
                 /* Implicitly fall back to now() if we never ran
@@ -2770,8 +2778,7 @@ _public_ int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec) {
                 *usec = e->timestamp.monotonic;
                 break;
 
-        case CLOCK_BOOTTIME:
-        case CLOCK_BOOTTIME_ALARM:
+        default:
                 *usec = e->timestamp_boottime;
                 break;
         }
diff --git a/src/libsystemd/sd-event/test-event.c b/src/libsystemd/sd-event/test-event.c
index 9417a8d1d1..c605b18ae9 100644
--- a/src/libsystemd/sd-event/test-event.c
+++ b/src/libsystemd/sd-event/test-event.c
@@ -264,6 +264,30 @@ static void test_basic(void) {
         safe_close_pair(k);
 }
 
+static void test_sd_event_now(void) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        uint64_t event_now;
+
+        assert_se(sd_event_new(&e) >= 0);
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME_ALARM, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME_ALARM, &event_now) > 0);
+        assert_se(sd_event_now(e, -1, &event_now) == -EOPNOTSUPP);
+        assert_se(sd_event_now(e, 900 /* arbitrary big number */, &event_now) == -EOPNOTSUPP);
+
+        assert_se(sd_event_run(e, 0) == 0);
+
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME_ALARM, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME_ALARM, &event_now) == 0);
+        assert_se(sd_event_now(e, -1, &event_now) == -EOPNOTSUPP);
+        assert_se(sd_event_now(e, 900 /* arbitrary big number */, &event_now) == -EOPNOTSUPP);
+}
+
 static int last_rtqueue_sigval = 0;
 static int n_rtqueue = 0;
 
@@ -324,7 +348,11 @@ static void test_rtqueue(void) {
 
 int main(int argc, char *argv[]) {
 
+        log_set_max_level(LOG_DEBUG);
+        log_parse_environment();
+
         test_basic();
+        test_sd_event_now();
         test_rtqueue();
 
         return 0;
diff --git a/src/libsystemd/sd-login/sd-login.c b/src/libsystemd/sd-login/sd-login.c
index 4b46eeb533..ef240c3531 100644
--- a/src/libsystemd/sd-login/sd-login.c
+++ b/src/libsystemd/sd-login/sd-login.c
@@ -810,7 +810,7 @@ _public_ int sd_get_uids(uid_t **users) {
 
                 errno = 0;
                 de = readdir(d);
-                if (!de && errno != 0)
+                if (!de && errno > 0)
                         return -errno;
 
                 if (!de)
diff --git a/src/libsystemd/sd-netlink/netlink-types.c b/src/libsystemd/sd-netlink/netlink-types.c
index 135354e5f3..be4ab1373d 100644
--- a/src/libsystemd/sd-netlink/netlink-types.c
+++ b/src/libsystemd/sd-netlink/netlink-types.c
@@ -96,15 +96,6 @@ static const NLType rtnl_link_info_data_macvlan_types[] = {
         [IFLA_MACVLAN_FLAGS] = { .type = NETLINK_TYPE_U16 },
 };
 
-static const NLType rtnl_link_bridge_management_types[] = {
-        [IFLA_BRIDGE_FLAGS]     = { .type = NETLINK_TYPE_U16 },
-        [IFLA_BRIDGE_MODE]      = { .type = NETLINK_TYPE_U16 },
-/*
-        [IFLA_BRIDGE_VLAN_INFO] = { .type = NETLINK_TYPE_BINARY,
-                                    .len = sizeof(struct bridge_vlan_info), },
-*/
-};
-
 static const NLType rtnl_link_info_data_bridge_types[] = {
         [IFLA_BR_FORWARD_DELAY]  = { .type = NETLINK_TYPE_U32 },
         [IFLA_BR_HELLO_TIME]     = { .type = NETLINK_TYPE_U32 },
diff --git a/src/locale/localed.c b/src/locale/localed.c
index 5ca41331bd..8ab845eb80 100644
--- a/src/locale/localed.c
+++ b/src/locale/localed.c
@@ -539,7 +539,7 @@ static int read_next_mapping(const char* filename,
                 if (!fgets(line, sizeof(line), f)) {
 
                         if (ferror(f))
-                                return errno ? -errno : -EIO;
+                                return errno > 0 ? -errno : -EIO;
 
                         return 0;
                 }
diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index d51330fb85..2e14aa2d95 100644
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -139,7 +139,7 @@ int manager_add_user_by_uid(Manager *m, uid_t uid, User **_user) {
         errno = 0;
         p = getpwuid(uid);
         if (!p)
-                return errno ? -errno : -ENOENT;
+                return errno > 0 ? -errno : -ENOENT;
 
         return manager_add_user(m, uid, p->pw_gid, p->pw_name, _user);
 }
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 4631f5fc90..9eda4638e5 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -124,7 +124,6 @@ int manager_get_seat_from_creds(Manager *m, sd_bus_message *message, const char
                         return r;
 
                 seat = session->seat;
-
                 if (!seat)
                         return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_SEAT, "Session has no seat.");
         } else {
@@ -1111,7 +1110,7 @@ static int method_set_user_linger(sd_bus_message *message, void *userdata, sd_bu
         errno = 0;
         pw = getpwuid(uid);
         if (!pw)
-                return errno ? -errno : -ENOENT;
+                return errno > 0 ? -errno : -ENOENT;
 
         r = bus_verify_polkit_async(
                         message,
@@ -1995,7 +1994,7 @@ static int method_schedule_shutdown(sd_bus_message *message, void *userdata, sd_
 
         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_AUGMENT|SD_BUS_CREDS_TTY|SD_BUS_CREDS_UID, &creds);
         if (r >= 0) {
-                const char *tty;
+                const char *tty = NULL;
 
                 (void) sd_bus_creds_get_uid(creds, &m->scheduled_shutdown_uid);
                 (void) sd_bus_creds_get_tty(creds, &tty);
@@ -2752,6 +2751,23 @@ int manager_send_changed(Manager *manager, const char *property, ...) {
                         l);
 }
 
+static int strdup_job(sd_bus_message *reply, char **job) {
+        const char *j;
+        char *copy;
+        int r;
+
+        r = sd_bus_message_read(reply, "o", &j);
+        if (r < 0)
+                return r;
+
+        copy = strdup(j);
+        if (!copy)
+                return -ENOMEM;
+
+        *job = copy;
+        return 1;
+}
+
 int manager_start_slice(
                 Manager *manager,
                 const char *slice,
@@ -2767,6 +2783,7 @@ int manager_start_slice(
 
         assert(manager);
         assert(slice);
+        assert(job);
 
         r = sd_bus_message_new_method_call(
                         manager->bus,
@@ -2820,22 +2837,7 @@ int manager_start_slice(
         if (r < 0)
                 return r;
 
-        if (job) {
-                const char *j;
-                char *copy;
-
-                r = sd_bus_message_read(reply, "o", &j);
-                if (r < 0)
-                        return r;
-
-                copy = strdup(j);
-                if (!copy)
-                        return -ENOMEM;
-
-                *job = copy;
-        }
-
-        return 1;
+        return strdup_job(reply, job);
 }
 
 int manager_start_scope(
@@ -2856,6 +2858,7 @@ int manager_start_scope(
         assert(manager);
         assert(scope);
         assert(pid > 1);
+        assert(job);
 
         r = sd_bus_message_new_method_call(
                         manager->bus,
@@ -2930,22 +2933,7 @@ int manager_start_scope(
         if (r < 0)
                 return r;
 
-        if (job) {
-                const char *j;
-                char *copy;
-
-                r = sd_bus_message_read(reply, "o", &j);
-                if (r < 0)
-                        return r;
-
-                copy = strdup(j);
-                if (!copy)
-                        return -ENOMEM;
-
-                *job = copy;
-        }
-
-        return 1;
+        return strdup_job(reply, job);
 }
 
 int manager_start_unit(Manager *manager, const char *unit, sd_bus_error *error, char **job) {
@@ -2954,6 +2942,7 @@ int manager_start_unit(Manager *manager, const char *unit, sd_bus_error *error,
 
         assert(manager);
         assert(unit);
+        assert(job);
 
         r = sd_bus_call_method(
                         manager->bus,
@@ -2967,22 +2956,7 @@ int manager_start_unit(Manager *manager, const char *unit, sd_bus_error *error,
         if (r < 0)
                 return r;
 
-        if (job) {
-                const char *j;
-                char *copy;
-
-                r = sd_bus_message_read(reply, "o", &j);
-                if (r < 0)
-                        return r;
-
-                copy = strdup(j);
-                if (!copy)
-                        return -ENOMEM;
-
-                *job = copy;
-        }
-
-        return 1;
+        return strdup_job(reply, job);
 }
 
 int manager_stop_unit(Manager *manager, const char *unit, sd_bus_error *error, char **job) {
@@ -2991,6 +2965,7 @@ int manager_stop_unit(Manager *manager, const char *unit, sd_bus_error *error, c
 
         assert(manager);
         assert(unit);
+        assert(job);
 
         r = sd_bus_call_method(
                         manager->bus,
@@ -3005,9 +2980,7 @@ int manager_stop_unit(Manager *manager, const char *unit, sd_bus_error *error, c
                 if (sd_bus_error_has_name(error, BUS_ERROR_NO_SUCH_UNIT) ||
                     sd_bus_error_has_name(error, BUS_ERROR_LOAD_FAILED)) {
 
-                        if (job)
-                                *job = NULL;
-
+                        *job = NULL;
                         sd_bus_error_free(error);
                         return 0;
                 }
@@ -3015,22 +2988,7 @@ int manager_stop_unit(Manager *manager, const char *unit, sd_bus_error *error, c
                 return r;
         }
 
-        if (job) {
-                const char *j;
-                char *copy;
-
-                r = sd_bus_message_read(reply, "o", &j);
-                if (r < 0)
-                        return r;
-
-                copy = strdup(j);
-                if (!copy)
-                        return -ENOMEM;
-
-                *job = copy;
-        }
-
-        return 1;
+        return strdup_job(reply, job);
 }
 
 int manager_abandon_scope(Manager *manager, const char *scope, sd_bus_error *error) {
diff --git a/src/login/logind-user.c b/src/login/logind-user.c
index 4ad9740e5e..98f8ea3c78 100644
--- a/src/login/logind-user.c
+++ b/src/login/logind-user.c
@@ -412,13 +412,12 @@ static int user_start_slice(User *u) {
                         u->manager->user_tasks_max,
                         &error,
                         &job);
-        if (r < 0) {
-                /* we don't fail due to this, let's try to continue */
-                if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
-                        log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)", u->slice, bus_error_message(&error, r), error.name);
-        } else {
+        if (r >= 0)
                 u->slice_job = job;
-        }
+        else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
+                /* we don't fail due to this, let's try to continue */
+                log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
+                                u->slice, bus_error_message(&error, r), error.name);
 
         return 0;
 }
@@ -868,7 +867,7 @@ int config_parse_tmpfs_size(
 
                 errno = 0;
                 ul = strtoul(rvalue, &f, 10);
-                if (errno != 0 || f != e) {
+                if (errno > 0 || f != e) {
                         log_syntax(unit, LOG_ERR, filename, line, errno, "Failed to parse percentage value, ignoring: %s", rvalue);
                         return 0;
                 }
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index c6b5b1ec44..e448dd2035 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -910,7 +910,7 @@ static int method_map_from_machine_user(sd_bus_message *message, void *userdata,
                 if (k < 0 && feof(f))
                         break;
                 if (k != 3) {
-                        if (ferror(f) && errno != 0)
+                        if (ferror(f) && errno > 0)
                                 return -errno;
 
                         return -EIO;
@@ -968,7 +968,7 @@ static int method_map_to_machine_user(sd_bus_message *message, void *userdata, s
                         if (k < 0 && feof(f))
                                 break;
                         if (k != 3) {
-                                if (ferror(f) && errno != 0)
+                                if (ferror(f) && errno > 0)
                                         return -errno;
 
                                 return -EIO;
@@ -1028,7 +1028,7 @@ static int method_map_from_machine_group(sd_bus_message *message, void *groupdat
                 if (k < 0 && feof(f))
                         break;
                 if (k != 3) {
-                        if (ferror(f) && errno != 0)
+                        if (ferror(f) && errno > 0)
                                 return -errno;
 
                         return -EIO;
@@ -1086,7 +1086,7 @@ static int method_map_to_machine_group(sd_bus_message *message, void *groupdata,
                         if (k < 0 && feof(f))
                                 break;
                         if (k != 3) {
-                                if (ferror(f) && errno != 0)
+                                if (ferror(f) && errno > 0)
                                         return -errno;
 
                                 return -EIO;
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index 93867bedb7..9a5223ef01 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -1071,7 +1071,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
         /* Let's calculate the actual data size and update the field */
         rdlength = p->size - rdlength_offset - sizeof(uint16_t);
         if (rdlength > 0xFFFF) {
-                r = ENOSPC;
+                r = -ENOSPC;
                 goto fail;
         }
 
diff --git a/src/shared/ask-password-api.c b/src/shared/ask-password-api.c
index bc12f89f02..8de1445a96 100644
--- a/src/shared/ask-password-api.c
+++ b/src/shared/ask-password-api.c
@@ -71,7 +71,7 @@ static int lookup_key(const char *keyname, key_serial_t *ret) {
 
         serial = request_key("user", keyname, NULL, 0);
         if (serial == -1)
-                return -errno;
+                return negative_errno();
 
         *ret = serial;
         return 0;
diff --git a/src/shared/dropin.c b/src/shared/dropin.c
index 692e8b8338..073a8396c5 100644
--- a/src/shared/dropin.c
+++ b/src/shared/dropin.c
@@ -156,7 +156,7 @@ static int iterate_dir(
 
                 errno = 0;
                 de = readdir(d);
-                if (!de && errno != 0)
+                if (!de && errno > 0)
                         return log_error_errno(errno, "Failed to read directory %s: %m", path);
 
                 if (!de)
diff --git a/src/sysusers/sysusers.c b/src/sysusers/sysusers.c
index 675f94906b..a7e8187f4f 100644
--- a/src/sysusers/sysusers.c
+++ b/src/sysusers/sysusers.c
@@ -280,7 +280,7 @@ static int putgrent_with_members(const struct group *gr, FILE *group) {
 
                         errno = 0;
                         if (putgrent(&t, group) != 0)
-                                return errno ? -errno : -EIO;
+                                return errno > 0 ? -errno : -EIO;
 
                         return 1;
                 }
@@ -288,7 +288,7 @@ static int putgrent_with_members(const struct group *gr, FILE *group) {
 
         errno = 0;
         if (putgrent(gr, group) != 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return 0;
 }
@@ -330,7 +330,7 @@ static int putsgent_with_members(const struct sgrp *sg, FILE *gshadow) {
 
                         errno = 0;
                         if (putsgent(&t, gshadow) != 0)
-                                return errno ? -errno : -EIO;
+                                return errno > 0 ? -errno : -EIO;
 
                         return 1;
                 }
@@ -338,7 +338,7 @@ static int putsgent_with_members(const struct sgrp *sg, FILE *gshadow) {
 
         errno = 0;
         if (putsgent(sg, gshadow) != 0)
-                return errno ? -errno : -EIO;
+                return errno > 0 ? -errno : -EIO;
 
         return 0;
 }
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index f9a759e223..bb81ff5e3a 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -1075,7 +1075,7 @@ static int item_do_children(Item *i, const char *path, action_t action) {
                 errno = 0;
                 de = readdir(d);
                 if (!de) {
-                        if (errno != 0 && r == 0)
+                        if (errno > 0 && r == 0)
                                 r = -errno;
 
                         break;
diff --git a/src/udev/udev-builtin-blkid.c b/src/udev/udev-builtin-blkid.c
index 0b1ae706e7..018b4dc596 100644
--- a/src/udev/udev-builtin-blkid.c
+++ b/src/udev/udev-builtin-blkid.c
@@ -124,7 +124,7 @@ static int find_gpt_root(struct udev_device *dev, blkid_probe pr, bool test) {
         errno = 0;
         pl = blkid_probe_get_partitions(pr);
         if (!pl)
-                return errno ? -errno : -ENOMEM;
+                return errno > 0 ? -errno : -ENOMEM;
 
         nvals = blkid_partlist_numof_partitions(pl);
         for (i = 0; i < nvals; i++) {
diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 366e7fbb87..8627a81ec2 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -1652,7 +1652,8 @@ exit:
 
 int main(int argc, char *argv[]) {
         _cleanup_free_ char *cgroup = NULL;
-        int r, fd_ctrl, fd_uevent;
+        _cleanup_close_ int fd_ctrl = -1, fd_uevent = -1;
+        int r;
 
         log_set_target(LOG_TARGET_AUTO);
         log_parse_environment();