path-util: Add a helper for checking paths

The difference with the already existing path_equal_or_inode_same function is
that the new one does not swallow errors.

src/basic/path-util.c

@@ -525,6 +525,18 @@ int path_compare_filename(const char *a, const char *b) {
         return strcmp(fa, fb);
 }
 
+int path_equal_or_inode_same_full(const char *a, const char *b, int flags) {
+        /* Returns true if paths are of the same entry, false if not, <0 on error. */
+
+        if (path_equal(a, b))
+                return 1;
+
+        if (!a || !b)
+                return 0;
+
+        return inode_same(a, b, flags);
+}
+
 char* path_extend_internal(char **x, ...) {
         size_t sz, old_sz;
         char *q, *nx;

src/basic/path-util.h

@@ -68,8 +68,9 @@ static inline bool path_equal_filename(const char *a, const char *b) {
         return path_compare_filename(a, b) == 0;
 }
 
+int path_equal_or_inode_same_full(const char *a, const char *b, int flags);
 static inline bool path_equal_or_inode_same(const char *a, const char *b, int flags) {
-        return path_equal(a, b) || inode_same(a, b, flags) > 0;
+        return path_equal_or_inode_same_full(a, b, flags) > 0;
 }
 
 char* path_extend_internal(char **x, ...);