[PATCH 3/5] write_file(): introduce an explicit WRITE_FILE_GENTLY request

[Junio C Hamano <gitster@pobox.com>]

All callers except for two ask this function to die upon error by
passing fatal=1; turn the parameter to a more generic "unsigned flag"
bag of bits, introduce an explicit WRITE_FILE_GENTLY bit and change
these two callers to pass that bit.

This is in preparation to add one more bit to this flag word.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 cache.h     | 15 ++++++++++++++-
 setup.c     |  2 +-
 transport.c |  2 +-
 wrapper.c   |  3 ++-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/cache.h b/cache.h
index 6bb7119..f105235 100644
--- a/cache.h
+++ b/cache.h
@@ -1539,8 +1539,21 @@ static inline ssize_t write_str_in_full(int fd, const char *str)
 {
 	return write_in_full(fd, str, strlen(str));
 }
+
+/*
+ * Create a new file by specifying its full contents via fmt and the
+ * remainder of args that are used like 'printf()' args.  Die upon
+ * an error unless WRITE_FILE_GENTLY flag is set, in which case return
+ * a negative number to signal an error.
+ *
+ * For historical reasons, the LSB of flags word is set by many
+ * callers to explicitly ask the function to die upon error, but now
+ * it is the default.
+ */
+#define WRITE_FILE_UNUSED_0 (1<<0)
+#define WRITE_FILE_GENTLY (1<<1)
 __attribute__((format (printf, 3, 4)))
-extern int write_file(const char *path, int fatal, const char *fmt, ...);
+extern int write_file(const char *path, unsigned flags, const char *fmt, ...);
 
 /* pager.c */
 extern void setup_pager(void);
diff --git a/setup.c b/setup.c
index 5f9f07d..718f4e1 100644
--- a/setup.c
+++ b/setup.c
@@ -404,7 +404,7 @@ static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 
 	strbuf_addf(&path, "%s/gitfile", gitdir);
 	if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
-		write_file(path.buf, 0, "%s\n", gitfile);
+		write_file(path.buf, WRITE_FILE_GENTLY, "%s\n", gitfile);
 	strbuf_release(&path);
 }
 
diff --git a/transport.c b/transport.c
index 40692f8..e1821a4 100644
--- a/transport.c
+++ b/transport.c
@@ -291,7 +291,7 @@ static int write_one_ref(const char *name, const struct object_id *oid,
 
 	strbuf_addstr(buf, name);
 	if (safe_create_leading_directories(buf->buf) ||
-	    write_file(buf->buf, 0, "%s\n", oid_to_hex(oid)))
+	    write_file(buf->buf, WRITE_FILE_GENTLY, "%s\n", oid_to_hex(oid)))
 		return error("problems writing temporary file %s: %s",
 			     buf->buf, strerror(errno));
 	strbuf_setlen(buf, len);
diff --git a/wrapper.c b/wrapper.c
index e451463..68d45b6 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -621,8 +621,9 @@ char *xgetcwd(void)
 	return strbuf_detach(&sb, NULL);
 }
 
-int write_file(const char *path, int fatal, const char *fmt, ...)
+int write_file(const char *path, unsigned flags, const char *fmt, ...)
 {
+	int fatal = !(flags & WRITE_FILE_GENTLY);
 	struct strbuf sb = STRBUF_INIT;
 	va_list params;
 	int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
-- 
2.5.0-568-g53a3e28