diff-lib.c: constness strengthening

The internal implementation of diff-index codepath used to use non const
pointer to pass sha1 around, but it did not have to.  With this, we can
also lose the private no_sha1[] array, as we can use the public null_sha1[]
array that exists exactly for the same purpose.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-lib.c b/diff-lib.c
index 94b150e830c5d9bd828a5e050166eed27e0b0e62..4581b594d0a65d5bbe782b1db5d69f33189a0e50 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -472,22 +472,21 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 static void diff_index_show_file(struct rev_info *revs,
                                 const char *prefix,
                                 struct cache_entry *ce,
-                                unsigned char *sha1, unsigned int mode)
+                                const unsigned char *sha1, unsigned int mode)
 {
        diff_addremove(&revs->diffopt, prefix[0], mode,
                       sha1, ce->name, NULL);
 }
 
 static int get_stat_data(struct cache_entry *ce,
-                        unsigned char **sha1p,
+                        const unsigned char **sha1p,
                         unsigned int *modep,
                         int cached, int match_missing)
 {
-       unsigned char *sha1 = ce->sha1;
+       const unsigned char *sha1 = ce->sha1;
        unsigned int mode = ce->ce_mode;
 
        if (!cached) {
-               static unsigned char no_sha1[20];
                int changed;
                struct stat st;
                if (lstat(ce->name, &st) < 0) {
@@ -501,7 +500,7 @@ static int get_stat_data(struct cache_entry *ce,
                changed = ce_match_stat(ce, &st, 0);
                if (changed) {
                        mode = ce_mode_from_stat(ce, st.st_mode);
-                       sha1 = no_sha1;
+                       sha1 = null_sha1;
                }
        }
 
@@ -514,7 +513,7 @@ static void show_new_file(struct rev_info *revs,
                          struct cache_entry *new,
                          int cached, int match_missing)
 {
-       unsigned char *sha1;
+       const unsigned char *sha1;
        unsigned int mode;
 
        /* New file in the index: it might actually be different in
@@ -533,7 +532,7 @@ static int show_modified(struct rev_info *revs,
                         int cached, int match_missing)
 {
        unsigned int mode, oldmode;
-       unsigned char *sha1;
+       const unsigned char *sha1;
 
        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
                if (report_missing)