blame: show "previous" information in --porcelain/--incremental format
[gitweb.git] / unpack-trees.c
index da68557b17650f7739ad12b9d5c94cca1a1f2d4f..e59d144d28164f2451784513105f6269f0e9167c 100644 (file)
@@ -8,6 +8,36 @@
 #include "progress.h"
 #include "refs.h"
 
+/*
+ * Error messages expected by scripts out of plumbing commands such as
+ * read-tree.  Non-scripted Porcelain is not required to use these messages
+ * and in fact are encouraged to reword them to better suit their particular
+ * situation better.  See how "git checkout" replaces not_uptodate_file to
+ * explain why it does not allow switching between branches when you have
+ * local changes, for example.
+ */
+static struct unpack_trees_error_msgs unpack_plumbing_errors = {
+       /* would_overwrite */
+       "Entry '%s' would be overwritten by merge. Cannot merge.",
+
+       /* not_uptodate_file */
+       "Entry '%s' not uptodate. Cannot merge.",
+
+       /* not_uptodate_dir */
+       "Updating '%s' would lose untracked files in it",
+
+       /* would_lose_untracked */
+       "Untracked working tree file '%s' would be %s by merge.",
+
+       /* bind_overlap */
+       "Entry '%s' overlaps with '%s'.  Cannot bind.",
+};
+
+#define ERRORMSG(o,fld) \
+       ( ((o) && (o)->msgs.fld) \
+       ? ((o)->msgs.fld) \
+       : (unpack_plumbing_errors.fld) )
+
 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
        unsigned int set, unsigned int clear)
 {
@@ -26,11 +56,12 @@ static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
  * directories, in case this unlink is the removal of the
  * last entry in the directory -- empty directories are removed.
  */
-static void unlink_entry(char *name, char *last_symlink)
+static void unlink_entry(struct cache_entry *ce)
 {
        char *cp, *prev;
+       char *name = ce->name;
 
-       if (has_symlink_leading_path(name, last_symlink))
+       if (has_symlink_leading_path(ce_namelen(ce), ce->name))
                return;
        if (unlink(name))
                return;
@@ -54,13 +85,13 @@ static void unlink_entry(char *name, char *last_symlink)
 }
 
 static struct checkout state;
-static void check_updates(struct unpack_trees_options *o)
+static int check_updates(struct unpack_trees_options *o)
 {
        unsigned cnt = 0, total = 0;
        struct progress *progress = NULL;
-       char last_symlink[PATH_MAX];
        struct index_state *index = &o->result;
        int i;
+       int errs = 0;
 
        if (o->update && o->verbose_update) {
                for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
@@ -74,28 +105,32 @@ static void check_updates(struct unpack_trees_options *o)
                cnt = 0;
        }
 
-       *last_symlink = '\0';
        for (i = 0; i < index->cache_nr; i++) {
                struct cache_entry *ce = index->cache[i];
 
-               if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
-                       display_progress(progress, ++cnt);
                if (ce->ce_flags & CE_REMOVE) {
+                       display_progress(progress, ++cnt);
                        if (o->update)
-                               unlink_entry(ce->name, last_symlink);
+                               unlink_entry(ce);
                        remove_index_entry_at(&o->result, i);
                        i--;
                        continue;
                }
+       }
+
+       for (i = 0; i < index->cache_nr; i++) {
+               struct cache_entry *ce = index->cache[i];
+
                if (ce->ce_flags & CE_UPDATE) {
+                       display_progress(progress, ++cnt);
                        ce->ce_flags &= ~CE_UPDATE;
                        if (o->update) {
-                               checkout_entry(ce, &state, NULL);
-                               *last_symlink = '\0';
+                               errs |= checkout_entry(ce, &state, NULL);
                        }
                }
        }
        stop_progress(&progress);
+       return errs != 0;
 }
 
 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
@@ -116,7 +151,6 @@ static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_option
                        add_entry(o, ce, 0, 0);
                        return 0;
                }
-               return 0;
        }
        return call_unpack_fn(src, o);
 }
@@ -124,7 +158,7 @@ static int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_option
 int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
 {
        int i;
-       struct tree_desc t[3];
+       struct tree_desc t[MAX_UNPACK_TREES];
        struct traverse_info newinfo;
        struct name_entry *p;
 
@@ -144,8 +178,7 @@ int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conf
                        sha1 = names[i].sha1;
                fill_tree_descriptor(t+i, sha1);
        }
-       traverse_trees(n, t, &newinfo);
-       return 0;
+       return traverse_trees(n, t, &newinfo);
 }
 
 /*
@@ -287,7 +320,6 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
                                                add_entry(o, ce, 0, 0);
                                                return mask;
                                        }
-                                       continue;
                                }
                                src[0] = ce;
                        }
@@ -306,7 +338,9 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
                        if (src[0])
                                conflicts |= 1;
                }
-               traverse_trees_recursive(n, dirmask, conflicts, names, info);
+               if (traverse_trees_recursive(n, dirmask, conflicts,
+                                            names, info) < 0)
+                       return -1;
                return mask;
        }
 
@@ -324,12 +358,17 @@ static int unpack_failed(struct unpack_trees_options *o, const char *message)
        return -1;
 }
 
+/*
+ * N-way merge "len" trees.  Returns 0 on success, -1 on failure to manipulate the
+ * resulting index, -2 on failure to reflect the changes to the work tree.
+ */
 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
 {
+       int ret;
        static struct cache_entry *dfc;
 
-       if (len > 4)
-               die("unpack_trees takes at most four trees");
+       if (len > MAX_UNPACK_TREES)
+               die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
        memset(&state, 0, sizeof(state));
        state.base_dir = "";
        state.force = 1;
@@ -337,6 +376,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
        state.refresh_cache = 1;
 
        memset(&o->result, 0, sizeof(o->result));
+       o->result.initialized = 1;
+       if (o->src_index)
+               o->result.timestamp = o->src_index->timestamp;
        o->merge_size = len;
 
        if (!dfc)
@@ -368,18 +410,17 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
                return unpack_failed(o, "Merge requires file-level merging");
 
        o->src_index = NULL;
-       check_updates(o);
+       ret = check_updates(o) ? (-2) : 0;
        if (o->dst_index)
                *o->dst_index = o->result;
-       return 0;
+       return ret;
 }
 
 /* Here come the merge functions */
 
-static int reject_merge(struct cache_entry *ce)
+static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
 {
-       return error("Entry '%s' would be overwritten by merge. Cannot merge.",
-                    ce->name);
+       return error(ERRORMSG(o, would_overwrite), ce->name);
 }
 
 static int same(struct cache_entry *a, struct cache_entry *b)
@@ -423,7 +464,7 @@ static int verify_uptodate(struct cache_entry *ce,
        if (errno == ENOENT)
                return 0;
        return o->gently ? -1 :
-               error("Entry '%s' not uptodate. Cannot merge.", ce->name);
+               error(ERRORMSG(o, not_uptodate_file), ce->name);
 }
 
 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
@@ -510,12 +551,27 @@ static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
        i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
        if (i)
                return o->gently ? -1 :
-                       error("Updating '%s' would lose untracked files in it",
-                             ce->name);
+                       error(ERRORMSG(o, not_uptodate_dir), ce->name);
        free(pathbuf);
        return cnt;
 }
 
+/*
+ * This gets called when there was no index entry for the tree entry 'dst',
+ * but we found a file in the working tree that 'lstat()' said was fine,
+ * and we're on a case-insensitive filesystem.
+ *
+ * See if we can find a case-insensitive match in the index that also
+ * matches the stat information, and assume it's that other file!
+ */
+static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
+{
+       struct cache_entry *src;
+
+       src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
+       return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID);
+}
+
 /*
  * We do not want to remove or overwrite a working tree file that
  * is not tracked, unless it is ignored.
@@ -528,12 +584,23 @@ static int verify_absent(struct cache_entry *ce, const char *action,
        if (o->index_only || o->reset || !o->update)
                return 0;
 
-       if (has_symlink_leading_path(ce->name, NULL))
+       if (has_symlink_leading_path(ce_namelen(ce), ce->name))
                return 0;
 
        if (!lstat(ce->name, &st)) {
                int cnt;
                int dtype = ce_to_dtype(ce);
+               struct cache_entry *result;
+
+               /*
+                * It may be that the 'lstat()' succeeded even though
+                * target 'ce' was absent, because there is an old
+                * entry that is different only in case..
+                *
+                * Ignore that lstat() if it matches.
+                */
+               if (ignore_case && icase_exists(o, ce, &st))
+                       return 0;
 
                if (o->dir && excluded(o->dir, ce->name, &dtype))
                        /*
@@ -577,16 +644,14 @@ static int verify_absent(struct cache_entry *ce, const char *action,
                 * delete this path, which is in a subdirectory that
                 * is being replaced with a blob.
                 */
-               cnt = index_name_pos(&o->result, ce->name, strlen(ce->name));
-               if (0 <= cnt) {
-                       struct cache_entry *ce = o->result.cache[cnt];
-                       if (ce->ce_flags & CE_REMOVE)
+               result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
+               if (result) {
+                       if (result->ce_flags & CE_REMOVE)
                                return 0;
                }
 
                return o->gently ? -1 :
-                       error("Untracked working tree file '%s' "
-                             "would be %s by merge.", ce->name, action);
+                       error(ERRORMSG(o, would_lose_untracked), ce->name, action);
        }
        return 0;
 }
@@ -594,16 +659,19 @@ static int verify_absent(struct cache_entry *ce, const char *action,
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
                struct unpack_trees_options *o)
 {
+       int update = CE_UPDATE;
+
        if (old) {
                /*
                 * See if we can re-use the old CE directly?
                 * That way we get the uptodate stat info.
                 *
-                * This also removes the UPDATE flag on
-                * a match.
+                * This also removes the UPDATE flag on a match; otherwise
+                * we will end up overwriting local changes in the work tree.
                 */
                if (same(old, merge)) {
                        copy_cache_entry(merge, old);
+                       update = 0;
                } else {
                        if (verify_uptodate(old, o))
                                return -1;
@@ -616,7 +684,7 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
                invalidate_ce_path(merge, o);
        }
 
-       add_entry(o, merge, CE_UPDATE, CE_STAGEMASK);
+       add_entry(o, merge, update, CE_STAGEMASK);
        return 1;
 }
 
@@ -715,7 +783,7 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
        /* #14, #14ALT, #2ALT */
        if (remote && !df_conflict_head && head_match && !remote_match) {
                if (index && !same(index, remote) && !same(index, head))
-                       return o->gently ? -1 : reject_merge(index);
+                       return o->gently ? -1 : reject_merge(index, o);
                return merged_entry(remote, index, o);
        }
        /*
@@ -723,7 +791,7 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
         * make sure that it matches head.
         */
        if (index && !same(index, head))
-               return o->gently ? -1 : reject_merge(index);
+               return o->gently ? -1 : reject_merge(index, o);
 
        if (head) {
                /* #5ALT, #15 */
@@ -865,16 +933,25 @@ int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
                else {
                        /* all other failures */
                        if (oldtree)
-                               return o->gently ? -1 : reject_merge(oldtree);
+                               return o->gently ? -1 : reject_merge(oldtree, o);
                        if (current)
-                               return o->gently ? -1 : reject_merge(current);
+                               return o->gently ? -1 : reject_merge(current, o);
                        if (newtree)
-                               return o->gently ? -1 : reject_merge(newtree);
+                               return o->gently ? -1 : reject_merge(newtree, o);
                        return -1;
                }
        }
-       else if (newtree)
+       else if (newtree) {
+               if (oldtree && !o->initial_checkout) {
+                       /*
+                        * deletion of the path was staged;
+                        */
+                       if (same(oldtree, newtree))
+                               return 1;
+                       return reject_merge(oldtree, o);
+               }
                return merged_entry(newtree, current, o);
+       }
        return deleted_entry(oldtree, current, o);
 }
 
@@ -895,7 +972,7 @@ int bind_merge(struct cache_entry **src,
                             o->merge_size);
        if (a && old)
                return o->gently ? -1 :
-                       error("Entry '%s' overlaps with '%s'.  Cannot bind.", a->name, old->name);
+                       error(ERRORMSG(o, bind_overlap), a->name, old->name);
        if (!a)
                return keep_entry(old, o);
        else