[PATCH v10 08/20] index-helper: log warnings

[David Turner <dturner@twopensource.com>]

Instead of writing warnings to stderr, write them to a log.  Later, we'll
probably be daemonized, so writing to stderr will be pointless.

Signed-off-by: David Turner <dturner@twopensource.com>
---
 Documentation/git-index-helper.txt |  3 +++
 index-helper.c                     | 12 +++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-index-helper.txt b/Documentation/git-index-helper.txt
index f853960..e144752 100644
--- a/Documentation/git-index-helper.txt
+++ b/Documentation/git-index-helper.txt
@@ -57,6 +57,9 @@ command. The following commands are used to control the daemon:
 
 All commands and replies are terminated by a NUL byte.
 
+In the event of an error, messages may be written to
+$GIT_DIR/index-helper.log.
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/index-helper.c b/index-helper.c
index 65abfd0..a3a9b00 100644
--- a/index-helper.c
+++ b/index-helper.c
@@ -95,7 +95,8 @@ static void share_index(struct index_state *istate, struct shm *is)
 	if (shared_mmap_create(istate->mmap_size, &new_mmap,
 			       git_path("shm-index-%s",
 					sha1_to_hex(istate->sha1))) < 0) {
-		die("Failed to create shm-index file");
+		warning("Failed to create shm-index file");
+		exit(1);
 	}
 
 
@@ -321,8 +322,17 @@ int main(int argc, char **argv)
 	if (fd < 0)
 		die_errno(_("could not set up index-helper socket"));
 
+	if (detach) {
+		FILE *fp = fopen(git_path("index-helper.log"), "a");
+		if (!fp)
+			die("failed to open %s for writing",
+			    git_path("index-helper.log"));
+		set_error_handle(fp);
+	}
+
 	if (detach && daemonize(&daemonized))
 		die_errno(_("unable to detach"));
+
 	loop(fd, idle_in_seconds);
 
 	close(fd);
-- 
2.4.2.767.g62658d5-twtrsrc