Check if value has changed before writing it

2 files changed, 16 insertions, 1 deletions

diff --git a/common/test_textfile.c b/common/test_textfile.c
index 814c806b..1c001f46 100644
--- a/common/test_textfile.c
+++ b/common/test_textfile.c
@@ -62,6 +62,16 @@ int main(int argc, char *argv[])
 	else
 		free(str);
 
+	snprintf(value, sizeof(value), "Test");
+	if (textfile_put(filename, key, value) < 0)
+		fprintf(stderr, "%s (%d)\n", strerror(errno), errno);
+
+	if (textfile_put(filename, key, value) < 0)
+		fprintf(stderr, "%s (%d)\n", strerror(errno), errno);
+
+	if (textfile_put(filename, key, value) < 0)
+		fprintf(stderr, "%s (%d)\n", strerror(errno), errno);
+
 	if (textfile_del(filename, key) < 0) 
 		fprintf(stderr, "%s (%d)\n", strerror(errno), errno);
 
diff --git a/common/textfile.c b/common/textfile.c
index 36bde03f..895e3f3d 100644
--- a/common/textfile.c
+++ b/common/textfile.c
@@ -168,7 +168,8 @@ static int write_key(const char *pathname, const char *key, const char *value, i
 		goto unlock;
 	}
 
-	off = find_key(map, key, strlen(key), icase);
+	len = strlen(key);
+	off = find_key(map, key, len, icase);
 	if (!off) {
 		if (value) {
 			munmap(map, size);
@@ -186,6 +187,10 @@ static int write_key(const char *pathname, const char *key, const char *value, i
 		goto unmap;
 	}
 
+	if (value && (strlen(value) == end - off - len - 1) &&
+			!strncmp(off + len + 1, value, end - off - len - 1))
+		goto unmap;
+
 	len = strspn(end, "\r\n");
 	end += len;