[PATCH] git: add git_mkstemp()

Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -181,7 +181,10 @@ extern char *sha1_file_name(const unsigned char *sha1);
 extern char *sha1_pack_name(const unsigned char *sha1);
 extern char *sha1_pack_index_name(const unsigned char *sha1);
 
+int git_mkstemp(char *path, size_t n, const char *template);
+
 int safe_create_leading_directories(char *path);
+char *safe_strncpy(char *, const char *, size_t);
 
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 extern int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size);

path.c

@@ -58,3 +58,29 @@ char *git_path(const char *fmt, ...)
 		return bad_path;
 	return cleanup_path(pathname);
 }
+
+
+/* git_mkstemp() - create tmp file honoring TMPDIR variable */
+int git_mkstemp(char *path, size_t len, const char *template)
+{
+	char *env, *pch = path;
+
+	if ((env = getenv("TMPDIR")) == NULL) {
+		strcpy(pch, "/tmp/");
+		len -= 5;
+	} else
+		len -= snprintf(pch, len, "%s/", env);
+
+	safe_strncpy(pch, template, len);
+
+	return mkstemp(path);
+}
+
+
+char *safe_strncpy(char *dest, const char *src, size_t n)
+{
+	strncpy(dest, src, n);
+	dest[n - 1] = '\0';
+
+	return dest;
+}