clone: report duplicate entries on case-insensitive filesystems

diff --git a/unpack-trees.c b/unpack-trees.c
index cd0680f11e3580ef24e9140dd00a1e38f02557d8..213da8bbb4f90c5e1cbf572bd8640c6093d22e28 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -345,6 +345,46 @@ static struct progress *get_progress(struct unpack_trees_options *o)
        return start_delayed_progress(_("Checking out files"), total);
 }
 
+static void setup_collided_checkout_detection(struct checkout *state,
+                                             struct index_state *index)
+{
+       int i;
+
+       state->clone = 1;
+       for (i = 0; i < index->cache_nr; i++)
+               index->cache[i]->ce_flags &= ~CE_MATCHED;
+}
+
+static void report_collided_checkout(struct index_state *index)
+{
+       struct string_list list = STRING_LIST_INIT_NODUP;
+       int i;
+
+       for (i = 0; i < index->cache_nr; i++) {
+               struct cache_entry *ce = index->cache[i];
+
+               if (!(ce->ce_flags & CE_MATCHED))
+                       continue;
+
+               string_list_append(&list, ce->name);
+               ce->ce_flags &= ~CE_MATCHED;
+       }
+
+       list.cmp = fspathcmp;
+       string_list_sort(&list);
+
+       if (list.nr) {
+               warning(_("the following paths have collided (e.g. case-sensitive paths\n"
+                         "on a case-insensitive filesystem) and only one from the same\n"
+                         "colliding group is in the working tree:\n"));
+
+               for (i = 0; i < list.nr; i++)
+                       fprintf(stderr, "  '%s'\n", list.items[i].string);
+       }
+
+       string_list_clear(&list, 0);
+}
+
 static int check_updates(struct unpack_trees_options *o)
 {
        unsigned cnt = 0;
@@ -359,6 +399,9 @@ static int check_updates(struct unpack_trees_options *o)
        state.refresh_cache = 1;
        state.istate = index;
 
+       if (o->clone)
+               setup_collided_checkout_detection(&state, index);
+
        progress = get_progress(o);
 
        if (o->update)
@@ -423,6 +466,10 @@ static int check_updates(struct unpack_trees_options *o)
        errs |= finish_delayed_checkout(&state);
        if (o->update)
                git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
+
+       if (o->clone)
+               report_collided_checkout(index);
+
        return errs != 0;
 }