Add corner case tests for diff-index and diff-files
[gitweb.git] / diff-lib.c
index d85d8f34ba055ad7e02bf5d61ae4a675ce0be1d3..52dbac34a40b2ca7bcbb7c2343a0487e5cb90ccf 100644 (file)
@@ -9,6 +9,7 @@
 #include "revision.h"
 #include "cache-tree.h"
 #include "path-list.h"
+#include "unpack-trees.h"
 
 /*
  * diff-files
@@ -37,7 +38,7 @@ static int get_mode(const char *path, int *mode)
        if (!path || !strcmp(path, "/dev/null"))
                *mode = 0;
        else if (!strcmp(path, "-"))
-               *mode = ntohl(create_ce_mode(0666));
+               *mode = create_ce_mode(0666);
        else if (stat(path, &st))
                return error("Could not access '%s'", path);
        else
@@ -384,7 +385,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                                        continue;
                        }
                        else
-                               dpath->mode = ntohl(ce_mode_from_stat(ce, st.st_mode));
+                               dpath->mode = ce_mode_from_stat(ce, st.st_mode);
 
                        while (i < entries) {
                                struct cache_entry *nce = active_cache[i];
@@ -398,10 +399,10 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                                 */
                                stage = ce_stage(nce);
                                if (2 <= stage) {
-                                       int mode = ntohl(nce->ce_mode);
+                                       int mode = nce->ce_mode;
                                        num_compare_stages++;
                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
-                                       dpath->parent[stage-2].mode = ntohl(ce_mode_from_stat(nce, mode));
+                                       dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
                                        dpath->parent[stage-2].status =
                                                DIFF_STATUS_MODIFIED;
                                }
@@ -435,6 +436,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                                continue;
                }
 
+               if (ce_uptodate(ce))
+                       continue;
                if (lstat(ce->name, &st) < 0) {
                        if (errno != ENOENT && errno != ENOTDIR) {
                                perror(ce->name);
@@ -442,15 +445,15 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                        }
                        if (silent_on_removed)
                                continue;
-                       diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
+                       diff_addremove(&revs->diffopt, '-', ce->ce_mode,
                                       ce->sha1, ce->name, NULL);
                        continue;
                }
                changed = ce_match_stat(ce, &st, ce_option);
                if (!changed && !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
                        continue;
-               oldmode = ntohl(ce->ce_mode);
-               newmode = ntohl(ce_mode_from_stat(ce, st.st_mode));
+               oldmode = ce->ce_mode;
+               newmode = ce_mode_from_stat(ce, st.st_mode);
                diff_change(&revs->diffopt, oldmode, newmode,
                            ce->sha1, (changed ? null_sha1 : ce->sha1),
                            ce->name, NULL);
@@ -469,22 +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], ntohl(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) {
@@ -498,7 +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;
                }
        }
 
@@ -511,7 +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
@@ -530,7 +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)
@@ -550,14 +552,14 @@ static int show_modified(struct rev_info *revs,
                p->len = pathlen;
                memcpy(p->path, new->name, pathlen);
                p->path[pathlen] = 0;
-               p->mode = ntohl(mode);
+               p->mode = mode;
                hashclr(p->sha1);
                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
                p->parent[0].status = DIFF_STATUS_MODIFIED;
-               p->parent[0].mode = ntohl(new->ce_mode);
+               p->parent[0].mode = new->ce_mode;
                hashcpy(p->parent[0].sha1, new->sha1);
                p->parent[1].status = DIFF_STATUS_MODIFIED;
-               p->parent[1].mode = ntohl(old->ce_mode);
+               p->parent[1].mode = old->ce_mode;
                hashcpy(p->parent[1].sha1, old->sha1);
                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
                free(p);
@@ -569,89 +571,11 @@ static int show_modified(struct rev_info *revs,
            !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
                return 0;
 
-       mode = ntohl(mode);
-       oldmode = ntohl(oldmode);
-
        diff_change(&revs->diffopt, oldmode, mode,
                    old->sha1, sha1, old->name, NULL);
        return 0;
 }
 
-static int diff_cache(struct rev_info *revs,
-                     struct cache_entry **ac, int entries,
-                     const char **pathspec,
-                     int cached, int match_missing)
-{
-       while (entries) {
-               struct cache_entry *ce = *ac;
-               int same = (entries > 1) && ce_same_name(ce, ac[1]);
-
-               if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
-                       DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
-                       break;
-
-               if (!ce_path_match(ce, pathspec))
-                       goto skip_entry;
-
-               switch (ce_stage(ce)) {
-               case 0:
-                       /* No stage 1 entry? That means it's a new file */
-                       if (!same) {
-                               show_new_file(revs, ce, cached, match_missing);
-                               break;
-                       }
-                       /* Show difference between old and new */
-                       show_modified(revs, ac[1], ce, 1,
-                                     cached, match_missing);
-                       break;
-               case 1:
-                       /* No stage 3 (merge) entry?
-                        * That means it's been deleted.
-                        */
-                       if (!same) {
-                               diff_index_show_file(revs, "-", ce,
-                                                    ce->sha1, ce->ce_mode);
-                               break;
-                       }
-                       /* We come here with ce pointing at stage 1
-                        * (original tree) and ac[1] pointing at stage
-                        * 3 (unmerged).  show-modified with
-                        * report-missing set to false does not say the
-                        * file is deleted but reports true if work
-                        * tree does not have it, in which case we
-                        * fall through to report the unmerged state.
-                        * Otherwise, we show the differences between
-                        * the original tree and the work tree.
-                        */
-                       if (!cached &&
-                           !show_modified(revs, ce, ac[1], 0,
-                                          cached, match_missing))
-                               break;
-                       diff_unmerge(&revs->diffopt, ce->name,
-                                    ntohl(ce->ce_mode), ce->sha1);
-                       break;
-               case 3:
-                       diff_unmerge(&revs->diffopt, ce->name,
-                                    0, null_sha1);
-                       break;
-
-               default:
-                       die("impossible cache entry stage");
-               }
-
-skip_entry:
-               /*
-                * Ignore all the different stages for this file,
-                * we've handled the relevant cases now.
-                */
-               do {
-                       ac++;
-                       entries--;
-               } while (entries && ce_same_name(ce, ac[0]));
-       }
-       return 0;
-}
-
 /*
  * This turns all merge entries into "stage 3". That guarantees that
  * when we read in the new tree (into "stage 1"), we won't lose sight
@@ -664,24 +588,120 @@ static void mark_merge_entries(void)
                struct cache_entry *ce = active_cache[i];
                if (!ce_stage(ce))
                        continue;
-               ce->ce_flags |= htons(CE_STAGEMASK);
+               ce->ce_flags |= CE_STAGEMASK;
        }
 }
 
-int run_diff_index(struct rev_info *revs, int cached)
+/*
+ * This gets a mix of an existing index and a tree, one pathname entry
+ * at a time. The index entry may be a single stage-0 one, but it could
+ * also be multiple unmerged entries (in which case idx_pos/idx_nr will
+ * give you the position and number of entries in the index).
+ */
+static void do_oneway_diff(struct unpack_trees_options *o,
+       struct cache_entry *idx,
+       struct cache_entry *tree)
 {
-       int ret;
-       struct object *ent;
-       struct tree *tree;
-       const char *tree_name;
-       int match_missing = 0;
+       struct rev_info *revs = o->unpack_data;
+       int match_missing, cached;
 
        /*
         * Backward compatibility wart - "diff-index -m" does
-        * not mean "do not ignore merges", but totally different.
+        * not mean "do not ignore merges", but "match_missing".
+        *
+        * But with the revision flag parsing, that's found in
+        * "!revs->ignore_merges".
         */
-       if (!revs->ignore_merges)
-               match_missing = 1;
+       cached = o->index_only;
+       match_missing = !revs->ignore_merges;
+
+       if (cached && idx && ce_stage(idx)) {
+               if (tree)
+                       diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode, idx->sha1);
+               return;
+       }
+
+       /*
+        * Something added to the tree?
+        */
+       if (!tree) {
+               show_new_file(revs, idx, cached, match_missing);
+               return;
+       }
+
+       /*
+        * Something removed from the tree?
+        */
+       if (!idx) {
+               diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode);
+               return;
+       }
+
+       /* Show difference between old and new */
+       show_modified(revs, tree, idx, 1, cached, match_missing);
+}
+
+static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
+{
+       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++;
+       }
+}
+
+/*
+ * The unpack_trees() interface is designed for merging, so
+ * the different source entries are designed primarily for
+ * the source trees, with the old index being really mainly
+ * used for being replaced by the result.
+ *
+ * For diffing, the index is more important, and we only have a
+ * single tree.
+ *
+ * We're supposed to return how many index entries we want to skip.
+ *
+ * This wrapper makes it all more readable, and takes care of all
+ * 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)
+{
+       struct cache_entry *idx = src[0];
+       struct cache_entry *tree = src[1];
+       struct rev_info *revs = o->unpack_data;
+
+       if (idx && ce_stage(idx))
+               skip_same_name(idx, o);
+
+       /*
+        * Unpack-trees generates a DF/conflict entry if
+        * there was a directory in the index and a tree
+        * in the tree. From a diff standpoint, that's a
+        * delete of the tree and a create of the file.
+        */
+       if (tree == o->df_conflict_entry)
+               tree = NULL;
+
+       if (ce_path_match(idx ? idx : tree, revs->prune_data))
+               do_oneway_diff(o, idx, tree);
+
+       return 0;
+}
+
+int run_diff_index(struct rev_info *revs, int cached)
+{
+       struct object *ent;
+       struct tree *tree;
+       const char *tree_name;
+       struct unpack_trees_options opts;
+       struct tree_desc t;
 
        mark_merge_entries();
 
@@ -690,13 +710,23 @@ int run_diff_index(struct rev_info *revs, int cached)
        tree = parse_tree_indirect(ent->sha1);
        if (!tree)
                return error("bad tree object %s", tree_name);
-       if (read_tree(tree, 1, revs->prune_data))
-               return error("unable to read tree object %s", tree_name);
-       ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
-                        cached, match_missing);
+
+       memset(&opts, 0, sizeof(opts));
+       opts.head_idx = 1;
+       opts.index_only = 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))
+               exit(128);
+
        diffcore_std(&revs->diffopt);
        diff_flush(&revs->diffopt);
-       return ret;
+       return 0;
 }
 
 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
@@ -706,6 +736,8 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
        int i;
        struct cache_entry **dst;
        struct cache_entry *last = NULL;
+       struct unpack_trees_options opts;
+       struct tree_desc t;
 
        /*
         * This is used by git-blame to run diff-cache internally;
@@ -722,8 +754,7 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
                        cache_tree_invalidate_path(active_cache_tree,
                                                   ce->name);
                        last = ce;
-                       ce->ce_mode = 0;
-                       ce->ce_flags &= ~htons(CE_STAGEMASK);
+                       ce->ce_flags |= CE_REMOVE;
                }
                *dst++ = ce;
        }
@@ -734,8 +765,18 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
        tree = parse_tree_indirect(tree_sha1);
        if (!tree)
                die("bad tree object %s", sha1_to_hex(tree_sha1));
-       if (read_tree(tree, 1, opt->paths))
-               return error("unable to read tree %s", sha1_to_hex(tree_sha1));
-       return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
-                         1, 0);
+
+       memset(&opts, 0, sizeof(opts));
+       opts.head_idx = 1;
+       opts.index_only = 1;
+       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))
+               exit(128);
+       return 0;
 }