busctl: add and use strcmp_ptr()

In member_compare_func(), it compares interface, type and name of
members.  But as it can contain NULL pointer, it needs to check them
before calling strcmp().  So make it as a separate strcmp_ptr
function (named after streq_ptr) so that it can be used by others.

Also let streq_ptr() to use it in order to make the code simpler.

1 files changed, 4 insertions, 17 deletions

diff --git a/src/libsystemd/sd-bus/busctl.c b/src/libsystemd/sd-bus/busctl.c
index 6aaaf0e5ec..2f4d977d72 100644
--- a/src/libsystemd/sd-bus/busctl.c
+++ b/src/libsystemd/sd-bus/busctl.c
@@ -656,28 +656,15 @@ static int member_compare_func(const void *a, const void *b) {
         assert(x->type);
         assert(y->type);
 
-        if (!x->interface && y->interface)
-                return -1;
-        if (x->interface && !y->interface)
-                return 1;
-        if (x->interface && y->interface) {
-                d = strcmp(x->interface, y->interface);
-                if (d != 0)
-                        return d;
-        }
+        d = strcmp_ptr(x->interface, y->interface);
+        if (d != 0)
+                return d;
 
         d = strcmp(x->type, y->type);
         if (d != 0)
                 return d;
 
-        if (!x->name && y->name)
-                return -1;
-        if (x->name && !y->name)
-                return 1;
-        if (x->name && y->name)
-                return strcmp(x->name, y->name);
-
-        return 0;
+        return strcmp_ptr(x->name, y->name);
 }
 
 static int member_compare_funcp(const void *a, const void *b) {