From 8fe8eecbb42646495cbddba34c55c16c06011587 Mon Sep 17 00:00:00 2001
From: Oscar Spencer <oscar@grain-lang.org>
Date: Sat, 22 Apr 2023 22:38:09 +0200
Subject: [PATCH] fix: Return correct length of string in fd_prestat_get (#202)

---
 src/uvwasi.c                    | 4 ++--
 test/test-fd-prestat-dir-name.c | 7 ++++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/uvwasi.c b/src/uvwasi.c
index 38a6817..9e7fc76 100644
--- a/src/uvwasi.c
+++ b/src/uvwasi.c
@@ -1122,7 +1122,7 @@ uvwasi_errno_t uvwasi_fd_prestat_get(uvwasi_t* uvwasi,
   }
 
   buf->pr_type = UVWASI_PREOPENTYPE_DIR;
-  buf->u.dir.pr_name_len = strlen(wrap->path) + 1;
+  buf->u.dir.pr_name_len = strlen(wrap->path);
   err = UVWASI_ESUCCESS;
 exit:
   uv_mutex_unlock(&wrap->mutex);
@@ -1156,7 +1156,7 @@ uvwasi_errno_t uvwasi_fd_prestat_dir_name(uvwasi_t* uvwasi,
     goto exit;
   }
 
-  size = strlen(wrap->path) + 1;
+  size = strlen(wrap->path);
   if (size > (size_t) path_len) {
     err = UVWASI_ENOBUFS;
     goto exit;
diff --git a/test/test-fd-prestat-dir-name.c b/test/test-fd-prestat-dir-name.c
index 1778bb8..d9711a1 100644
--- a/test/test-fd-prestat-dir-name.c
+++ b/test/test-fd-prestat-dir-name.c
@@ -34,16 +34,17 @@ int main(void) {
   assert(err == 0);
   assert(prestat.pr_type == UVWASI_PREOPENTYPE_DIR);
   assert(prestat.u.dir.pr_name_len ==
-         strlen(init_options.preopens[0].mapped_path) + 1);
+         strlen(init_options.preopens[0].mapped_path));
 
   /* Verify uvwasi_fd_prestat_dir_name(). */
-  prestat_buf_size = prestat.u.dir.pr_name_len + 1;
-  prestat_buf = malloc(prestat_buf_size);
+  prestat_buf_size = prestat.u.dir.pr_name_len;
+  prestat_buf = malloc(prestat_buf_size + 1);
   assert(prestat_buf != NULL);
   err = uvwasi_fd_prestat_dir_name(&uvwasi,
                                    3,
                                    prestat_buf,
                                    prestat_buf_size);
+  prestat_buf[prestat_buf_size] = '\0';
   assert(err == 0);
   assert(strcmp(prestat_buf, init_options.preopens[0].mapped_path) == 0);
   free(prestat_buf);