Re: [PATCH v7 21/31] merge-recursive: add a new hashmap for storing file collisions

[Stefan Beller]

On Tue, Jan 30, 2018 at 3:25 PM, Elijah Newren  wrote:
> Directory renames with the ability to merge directories opens up the
> possibility of add/add/add/.../add conflicts, if each of the N
> directories being merged into one target directory all had a file with
> the same name.  We need a way to check for and report on such
> collisions; this hashmap will be used for this purpose.
>
> Signed-off-by: Elijah Newren 
> ---

The same comment on compiling applies here.
Nice to review, but it may not compile due to unused functions
that a strict compiler may not be happy about.

[PATCH v7 21/31] merge-recursive: add a new hashmap for storing file collisions

[Elijah Newren]

Directory renames with the ability to merge directories opens up the
possibility of add/add/add/.../add conflicts, if each of the N
directories being merged into one target directory all had a file with
the same name.  We need a way to check for and report on such
collisions; this hashmap will be used for this purpose.

Signed-off-by: Elijah Newren 
---
 merge-recursive.c | 23 +++
 merge-recursive.h |  7 +++
 2 files changed, 30 insertions(+)

diff --git a/merge-recursive.c b/merge-recursive.c
index 9e9ad45d2a..ac968ad2ae 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -84,6 +84,29 @@ static void dir_rename_entry_init(struct dir_rename_entry 
*entry,
string_list_init(>possible_new_dirs, 0);
 }
 
+static struct collision_entry *collision_find_entry(struct hashmap *hashmap,
+   char *target_file)
+{
+   struct collision_entry key;
+
+   hashmap_entry_init(, strhash(target_file));
+   key.target_file = target_file;
+   return hashmap_get(hashmap, , NULL);
+}
+
+static int collision_cmp(void *unused_cmp_data,
+const struct collision_entry *e1,
+const struct collision_entry *e2,
+const void *unused_keydata)
+{
+   return strcmp(e1->target_file, e2->target_file);
+}
+
+static void collision_init(struct hashmap *map)
+{
+   hashmap_init(map, (hashmap_cmp_fn) collision_cmp, NULL, 0);
+}
+
 static void flush_output(struct merge_options *o)
 {
if (o->buffer_output < 2 && o->obuf.len) {
diff --git a/merge-recursive.h b/merge-recursive.h
index d7f4cc80c1..e1be27f57c 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -37,6 +37,13 @@ struct dir_rename_entry {
struct string_list possible_new_dirs;
 };
 
+struct collision_entry {
+   struct hashmap_entry ent; /* must be the first member! */
+   char *target_file;
+   struct string_list source_files;
+   unsigned reported_already:1;
+};
+
 /* merge_trees() but with recursive ancestor consolidation */
 int merge_recursive(struct merge_options *o,
struct commit *h1,
-- 
2.16.1.106.gf69932adfe