Re: [PATCH] Fix some sparse warnings

[Jonathan Nieder <jrnieder@gmail.com>]

Hi,

Ramsay Jones wrote:

> Sparse issues some "Using plain integer as NULL pointer" warnings.
> Each warning relates to the use of an '{0}' initialiser expression
> in the declaration of an 'struct object_info'. The first field of
> this structure has pointer type. Thus, in order to suppress these
> warnings, we replace the initialiser expression with '{NULL}'.

I agree that this is worth solving but the fix feels like a move in
the wrong direction.  Before this patch, the initialization says
"= {0}", which basically means "memset it to 0".  Afterward, the
initializer depends on the order of fields in the struct.

How about something like the following?

diff --git i/cache.h w/cache.h
index f2915509..ba028b75 100644
--- i/cache.h
+++ w/cache.h
@@ -1124,6 +1124,7 @@ struct object_info {
 		} packed;
 	} u;
 };
+#define OBJECT_INFO_INIT { NULL, NULL, OI_CACHED, { { NULL, 0, 0 } } }
 extern int sha1_object_info_extended(const unsigned char *, struct object_info *);
 
 /* Dumb servers support */
diff --git i/sha1_file.c w/sha1_file.c
index 6baed676..2d812b8d 100644
--- i/sha1_file.c
+++ w/sha1_file.c
@@ -2421,7 +2421,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
 
 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
-	struct object_info oi = {0};
+	struct object_info oi = OBJECT_INFO_INIT;
 
 	oi.sizep = sizep;
 	return sha1_object_info_extended(sha1, &oi);
diff --git i/streaming.c w/streaming.c
index cac282f0..b4c40ad9 100644
--- i/streaming.c
+++ w/streaming.c
@@ -135,7 +135,7 @@ struct git_istream *open_istream(const unsigned char *sha1,
 				 struct stream_filter *filter)
 {
 	struct git_istream *st;
-	struct object_info oi = {0};
+	struct object_info oi = OBJECT_INFO_INIT;
 	const unsigned char *real = lookup_replace_object(sha1);
 	enum input_source src = istream_source(real, type, &oi);