From ed88bcfb7c15029f9fc95ee2380759a9eb782d46 Mon Sep 17 00:00:00 2001
From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Wed, 16 Jul 2014 18:59:49 -0400
Subject: Be more careful when checking for empty files

If we want to avoid reading a totally empty file, it seems better
to check after we have opened the file, not before.
---
 src/udev/net/link-config.c | 10 +++++-----
 src/udev/udev-rules.c      | 18 +++++++++++-------
 2 files changed, 16 insertions(+), 12 deletions(-)

(limited to 'src/udev')

diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c
index 73243fa107..512885f9c8 100644
--- a/src/udev/net/link-config.c
+++ b/src/udev/net/link-config.c
@@ -153,11 +153,6 @@ static int load_link(link_config_ctx *ctx, const char *filename) {
         assert(ctx);
         assert(filename);
 
-        if (null_or_empty_path(filename)) {
-                log_debug("skipping empty file: %s", filename);
-                return 0;
-        }
-
         file = fopen(filename, "re");
         if (!file) {
                 if (errno == ENOENT)
@@ -166,6 +161,11 @@ static int load_link(link_config_ctx *ctx, const char *filename) {
                         return -errno;
         }
 
+        if (null_or_empty_fd(fileno(file))) {
+                log_debug("Skipping empty file: %s", filename);
+                return 0;
+        }
+
         link = new0(link_config, 1);
         if (!link)
                 return log_oom();
diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c
index 85f78bcdef..9864016d14 100644
--- a/src/udev/udev-rules.c
+++ b/src/udev/udev-rules.c
@@ -1533,15 +1533,19 @@ static int parse_file(struct udev_rules *rules, const char *filename)
         int line_nr = 0;
         unsigned int i;
 
-        if (null_or_empty_path(filename)) {
-                log_debug("skip empty file: %s", filename);
-                return 0;
+        f = fopen(filename, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+                else
+                        return -errno;
         }
-        log_debug("read rules file: %s", filename);
 
-        f = fopen(filename, "re");
-        if (f == NULL)
-                return -1;
+        if (null_or_empty_fd(fileno(f))) {
+                log_debug("Skipping empty file: %s", filename);
+                return 0;
+        } else
+                log_debug("Reading rules file: %s", filename);
 
         first_token = rules->token_cur;
         filename_off = rules_add_string(rules, filename);
-- 
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