[PATCH 2/2] setup: don't fail if commondir reference is deleted.

[Michal Suchanek]

When adding wotktrees git can die in get_common_dir_noenv while
examining existing worktrees because the commondir file does not exist.
Rather than testing if the file exists before reading it handle ENOENT.

Signed-off-by: Michal Suchanek <msucha...@suse.de>
---
v2:
- do not test file existence first, just read it and handle ENOENT.
- handle zero size file correctly
---
 setup.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/setup.c b/setup.c
index ca9e8a949ed8..dd865f280d34 100644
--- a/setup.c
+++ b/setup.c
@@ -270,12 +270,20 @@ int get_common_dir_noenv(struct strbuf *sb, const char 
*gitdir)
 {
        struct strbuf data = STRBUF_INIT;
        struct strbuf path = STRBUF_INIT;
-       int ret = 0;
+       int ret;
 
        strbuf_addf(&path, "%s/commondir", gitdir);
-       if (file_exists(path.buf)) {
-               if (strbuf_read_file(&data, path.buf, 0) <= 0)
+       ret = strbuf_read_file(&data, path.buf, 0);
+       if (ret <= 0) {
+               /*
+                * if file is missing or zero size (just being written)
+                * assume default, bail otherwise
+                */
+               if (ret && errno != ENOENT)
                        die_errno(_("failed to read %s"), path.buf);
+               strbuf_addstr(sb, gitdir);
+               ret = 0;
+       } else {
                while (data.len && (data.buf[data.len - 1] == '\n' ||
                                    data.buf[data.len - 1] == '\r'))
                        data.len--;
@@ -286,8 +294,6 @@ int get_common_dir_noenv(struct strbuf *sb, const char 
*gitdir)
                strbuf_addbuf(&path, &data);
                strbuf_add_real_path(sb, path.buf);
                ret = 1;
-       } else {
-               strbuf_addstr(sb, gitdir);
        }
 
        strbuf_release(&data);
-- 
2.20.1