[PATCH] Make git prune remove temporary packs that look like write failures

[David Steven Tweed <d.s.tweed@reading.ac.uk>]

Write errors when repacking (eg, due to out-of-space conditions)
can leave temporary packs (and possibly other files beginning
with "tmp_") lying around which no existing
codepath removes and which aren't obvious to the casual user.
These can also be multi-megabyte files wasting noticeable space.
Unfortunately there's no way to definitely tell in builtin-prune
that a tmp_ file is not being used by a concurrent process.
However, it is documented that pruning should only be done
on a quiet repository. The names of removed files are printed.

Signed-off-by: David Tweed (david.tweed@gmail.com)
---

Per discussion of previous version, this now unconditionally
removes any tmp_ file existing when prune is run.

  builtin-prune.c |   25 +++++++++++++++++++++++++
  1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/builtin-prune.c b/builtin-prune.c
index b5e7684..9db3cf0 100644
--- a/builtin-prune.c
+++ b/builtin-prune.c
@@ -83,6 +83,30 @@ static void prune_object_dir(const char *path)
  	}
  }

+/*
+ * Write errors (particularly out of space) can result in
+ * failed temporary packs (and more rarely indexes and other
+ * files begining with "tmp_") accumulating in the
+ * object directory.
+ */
+static void remove_temporary_files(void)
+{
+	DIR *dir;
+	struct dirent *de;
+	char* dirname=get_object_directory();
+
+	dir = opendir(dirname);
+	while ((de = readdir(dir)) != NULL) {
+		if (strncmp(de->d_name, "tmp_", 4) == 0) {
+			char name[4096];
+			sprintf(name, "%s/%s", dirname, de->d_name);
+			printf("Removing abandoned pack %s\n", name);
+			unlink(name);
+		}
+	}
+	closedir(dir);
+}
+
  int cmd_prune(int argc, const char **argv, const char *prefix)
  {
  	int i;
@@ -115,5 +139,6 @@ int cmd_prune(int argc, const char **argv, const char *prefix)

  	sync();
  	prune_packed_objects(show_only);
+	remove_temporary_files();
  	return 0;
  }
-- 
1.5.4.19.g40d1a-dirty