git_mkstemp_mode, xmkstemp_mode: variants of gitmkstemps with mode argument.

gitmkstemps emulates the behavior of mkstemps, which is usually used
to create files in a shared directory like /tmp/, hence, it creates
files with permission 0600.

Add git_mkstemps_mode() that allows us to specify the desired mode, and
make git_mkstemps() a wrapper that always uses 0600 to call it. Later we
will use git_mkstemps_mode() when creating pack files.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 27 insertions, 2 deletions

diff --git a/cache.h b/cache.h
index d478eff1f3..0319637723 100644
--- a/cache.h
+++ b/cache.h
@@ -641,6 +641,10 @@ int git_mkstemp(char *path, size_t n, const char *template);
 
 int git_mkstemps(char *path, size_t n, const char *template, int suffix_len);
 
+/* set default permissions by passing mode arguments to open(2) */
+int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
+int git_mkstemp_mode(char *pattern, int mode);
+
 /*
  * NOTE NOTE NOTE!!
  *
diff --git a/path.c b/path.c
index ab2e3687ab..03d284ba8b 100644
--- a/path.c
+++ b/path.c
@@ -162,7 +162,7 @@ int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
 #undef TMP_MAX
 #define TMP_MAX 16384
 
-int gitmkstemps(char *pattern, int suffix_len)
+int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 {
 	static const char letters[] =
 		"abcdefghijklmnopqrstuvwxyz"
@@ -204,7 +204,7 @@ int gitmkstemps(char *pattern, int suffix_len)
 		template[4] = letters[v % num_letters]; v /= num_letters;
 		template[5] = letters[v % num_letters]; v /= num_letters;
 
-		fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, 0600);
+		fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
 		if (fd > 0)
 			return fd;
 		/*
@@ -226,6 +226,17 @@ int gitmkstemps(char *pattern, int suffix_len)
 	return -1;
 }
 
+int git_mkstemp_mode(char *pattern, int mode)
+{
+	/* mkstemp is just mkstemps with no suffix */
+	return git_mkstemps_mode(pattern, 0, mode);
+}
+
+int gitmkstemps(char *pattern, int suffix_len)
+{
+	return git_mkstemps_mode(pattern, suffix_len, 0600);
+}
+
 int validate_headref(const char *path)
 {
 	struct stat st;
diff --git a/wrapper.c b/wrapper.c
index 0e3e20a3fd..673762fde9 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -204,6 +204,16 @@ int xmkstemp(char *template)
 	return fd;
 }
 
+int xmkstemp_mode(char *template, int mode)
+{
+	int fd;
+
+	fd = git_mkstemp_mode(template, mode);
+	if (fd < 0)
+		die_errno("Unable to create temporary file");
+	return fd;
+}
+
 /*
  * zlib wrappers to make sure we don't silently miss errors
  * at init time.