[PATCH 3/4] unpack-trees: Fix same() for submodules

From: Stefan Beller <sbeller@google.com>
Date: Dec 20, 2017, 22:17 UTC
Message-ID: <20171220221725.129162-4-sbeller@google.com>
In-Reply-To: <20171220221725.129162-1-sbeller@google.com>

The function same(a, b) is used to check if two entries a and b are the same. As the index contains the staged files the same() function can be used to check if files between a given revision and the index are the same.

In case of submodules, the gitlink entry is showing up as not modified despite potential changes inside the submodule.

Fix the function to examine submodules by looking inside the submodule. This patch alone doesn't affect any correctness garantuees, but in combination with the next patch this fixes the new test introduced earlier in this series.

This may be a slight performance regression as now we have to inspect any submodule thouroughly.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 unpack-trees.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/unpack-trees.c b/unpack-trees.c
index bf8b602901..4d839e8edb 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1427,6 +1427,8 @@ static int same(const struct cache_entry *a, const struct cache_entry *b)
 		return 1;
 	if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
 		return 0;
+	if (S_ISGITLINK(b->ce_mode) && should_update_submodules())
+		return !oidcmp(&a->oid, &b->oid) && !is_submodule_modified(b->name, 0);
 	return a->ce_mode == b->ce_mode &&
 	       !oidcmp(&a->oid, &b->oid);
 }

-- 
2.15.1.620.gb9897f4670-goog