Add corner case tests for diff-index and diff-files

diff --git a/diff-lib.c b/diff-lib.c
index 94b150e830c5d9bd828a5e050166eed27e0b0e62..52dbac34a40b2ca7bcbb7c2343a0487e5cb90ccf 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)
@@ -601,8 +600,7 @@ static void mark_merge_entries(void)
  */
 static void do_oneway_diff(struct unpack_trees_options *o,
        struct cache_entry *idx,
-       struct cache_entry *tree,
-       int idx_pos, int idx_nr)
+       struct cache_entry *tree)
 {
        struct rev_info *revs = o->unpack_data;
        int match_missing, cached;
@@ -643,32 +641,19 @@ static void do_oneway_diff(struct unpack_trees_options *o,
        show_modified(revs, tree, idx, 1, cached, match_missing);
 }
 
-/*
- * Count how many index entries go with the first one
- */
-static inline int count_skip(const struct cache_entry *src, int pos)
+static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
 {
-       int skip = 1;
-
-       /* We can only have multiple entries if the first one is not stage-0 */
-       if (ce_stage(src)) {
-               struct cache_entry **p = active_cache + pos;
-               int namelen = ce_namelen(src);
-
-               for (;;) {
-                       const struct cache_entry *ce;
-                       pos++;
-                       if (pos >= active_nr)
-                               break;
-                       ce = *++p;
-                       if (ce_namelen(ce) != namelen)
-                               break;
-                       if (memcmp(ce->name, src->name, namelen))
-                               break;
-                       skip++;
-               }
+       int len = ce_namelen(ce);
+       const struct index_state *index = o->src_index;
+
+       while (o->pos < index->cache_nr) {
+               struct cache_entry *next = index->cache[o->pos];
+               if (len != ce_namelen(next))
+                       break;
+               if (memcmp(ce->name, next->name, len))
+                       break;
+               o->pos++;
        }
-       return skip;
 }
 
 /*
@@ -686,17 +671,14 @@ static inline int count_skip(const struct cache_entry *src, int pos)
  * the fairly complex unpack_trees() semantic requirements, including
  * the skipping, the path matching, the type conflict cases etc.
  */
-static int oneway_diff(struct cache_entry **src,
-       struct unpack_trees_options *o,
-       int index_pos)
+static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 {
-       int skip = 0;
        struct cache_entry *idx = src[0];
        struct cache_entry *tree = src[1];
        struct rev_info *revs = o->unpack_data;
 
-       if (index_pos >= 0)
-               skip = count_skip(idx, index_pos);
+       if (idx && ce_stage(idx))
+               skip_same_name(idx, o);
 
        /*
         * Unpack-trees generates a DF/conflict entry if
@@ -708,9 +690,9 @@ static int oneway_diff(struct cache_entry **src,
                tree = NULL;
 
        if (ce_path_match(idx ? idx : tree, revs->prune_data))
-               do_oneway_diff(o, idx, tree, index_pos, skip);
+               do_oneway_diff(o, idx, tree);
 
-       return skip;
+       return 0;
 }
 
 int run_diff_index(struct rev_info *revs, int cached)
@@ -735,6 +717,8 @@ int run_diff_index(struct rev_info *revs, int cached)
        opts.merge = 1;
        opts.fn = oneway_diff;
        opts.unpack_data = revs;
+       opts.src_index = &the_index;
+       opts.dst_index = NULL;
 
        init_tree_desc(&t, tree->buffer, tree->size);
        if (unpack_trees(1, &t, &opts))
@@ -788,6 +772,8 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
        opts.merge = 1;
        opts.fn = oneway_diff;
        opts.unpack_data = &revs;
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
 
        init_tree_desc(&t, tree->buffer, tree->size);
        if (unpack_trees(1, &t, &opts))