git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH] sha1_file: avoid bogus "file exists" error message

From
Joey Hess <joey@kitenet.net>
Date
Nov 20, 2008, 18:56 UTC
Message-ID
<20081120185628.GA25604@kodama.kitenet.net>
This avoids the following misleading error message:
error: unable to create temporary sha1 filename ./objects/15: File exists

mkstemp can fail for many reasons, one of which, ENOENT, can occur if the directory for the temp file doesn't exist. create_tmpfile tried to handle this case by always trying to mkdir the directory, even if it already existed. This caused errno to be clobbered, so one cannot tell why mkstemp really failed, and it truncated the buffer to just the directory name, resulting in the strange error message shown above.

Note that in both occasions that I've seen this failure, it has not been due to a missing directory, or bad permissions, but some other, unknown mkstemp failure mode that did not occur when I ran git again. This code could perhaps be made more robust by retrying mkstemp, in case it was a transient failure.

Signed-off-by: Joey Hess <joey@kitenet.net>
---
 sha1_file.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/sha1_file.c b/sha1_file.c
index ab2b520..927fb64 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2231,7 +2231,7 @@ static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
 	memcpy(buffer, filename, dirlen);
 	strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
 	fd = mkstemp(buffer);
-	if (fd < 0 && dirlen) {
+	if (fd < 0 && dirlen && errno == ENOENT) {
 		/* Make sure the directory exists */
 		memcpy(buffer, filename, dirlen);
 		buffer[dirlen-1] = 0;
-- 
1.5.6.5
Next: Joey Hess
Message 1 of 4 in “sha1_file: avoid bogus "file exists" error message”
  1. sha1_file: avoid bogus "file exists" error messageJoey Hess, Nov 20, 2008
  2. Joey HessNov 26, 2008
  3. Ian HiltNov 27, 2008
  4. Joey HessNov 28, 2008

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.