shared/path_simplify: return an unsigned value

2 files changed, 4 insertions, 1 deletions

diff --git a/src/user/lib/include/unistd.h b/src/user/lib/include/unistd.h
index 1f0c002..59af24b 100644
--- a/src/user/lib/include/unistd.h
+++ b/src/user/lib/include/unistd.h
@@ -19,6 +19,9 @@ char *getcwd(char *buf, size_t size);
  *                 except for the root dir. Includes the null byte.
  * If size isn't enough to fit the path, returns the amount of bytes needed to fit
  * it, including the null byte.
+ *
+ * Note that some errors are only detected if *out != NULL, so you must check the return
+ * value twice.
  * @return 0 on failure, length of the path otherwise */
 size_t absolutepath(char *out, const char *in, size_t size);
 
diff --git a/src/user/lib/unistd.c b/src/user/lib/unistd.c
index 1a50c3e..ce43551 100644
--- a/src/user/lib/unistd.c
+++ b/src/user/lib/unistd.c
@@ -163,7 +163,7 @@ size_t absolutepath(char *out, const char *in, size_t size) {
 
 	if (pos <= size) {
 		pos = path_simplify(out, out, pos);
-		if (pos > 0) out[pos] = '\0';
+		if (pos == 0) return 0;
 	}
 
 	if (pos + 1 <= size) out[pos] = '\0';