[PATCH 1/6] csum-file: make sha1write const-correct

[Jeff King <peff@peff.net>]

We do not modify the buffer we are asked to write; mark it
with const so that callers with const buffers do not get
unnecessary complaints from the compiler.

Signed-off-by: Jeff King <peff@peff.net>
---
 csum-file.c | 6 +++---
 csum-file.h | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/csum-file.c b/csum-file.c
index 53f5375..465971c 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -11,7 +11,7 @@
 #include "progress.h"
 #include "csum-file.h"
 
-static void flush(struct sha1file *f, void *buf, unsigned int count)
+static void flush(struct sha1file *f, const void *buf, unsigned int count)
 {
 	if (0 <= f->check_fd && count)  {
 		unsigned char check_buffer[8192];
@@ -86,13 +86,13 @@ int sha1write(struct sha1file *f, void *buf, unsigned int count)
 	return fd;
 }
 
-int sha1write(struct sha1file *f, void *buf, unsigned int count)
+int sha1write(struct sha1file *f, const void *buf, unsigned int count)
 {
 	while (count) {
 		unsigned offset = f->offset;
 		unsigned left = sizeof(f->buffer) - offset;
 		unsigned nr = count > left ? left : count;
-		void *data;
+		const void *data;
 
 		if (f->do_crc)
 			f->crc32 = crc32(f->crc32, buf, nr);
diff --git a/csum-file.h b/csum-file.h
index 3b540bd..9dedb03 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -34,7 +34,7 @@ extern int sha1close(struct sha1file *, unsigned char *, unsigned int);
 extern struct sha1file *sha1fd_check(const char *name);
 extern struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp);
 extern int sha1close(struct sha1file *, unsigned char *, unsigned int);
-extern int sha1write(struct sha1file *, void *, unsigned int);
+extern int sha1write(struct sha1file *, const void *, unsigned int);
 extern void sha1flush(struct sha1file *f);
 extern void crc32_begin(struct sha1file *);
 extern uint32_t crc32_end(struct sha1file *);
-- 
1.8.0.2.16.g72e2fc9