On 6/9/2021 4:33 PM, Derrick Stolee wrote:
> On 6/9/2021 4:11 AM, Elijah Newren wrote:
>> On Tue, Jun 8, 2021 at 11:32 PM Junio C Hamano <gitster@xxxxxxxxx> wrote:
>>>
>>> Elijah Newren <newren@xxxxxxxxx> writes:
>>>
>>> The tree-diff machinery takes two trees, walks them in parallel and
>>> repeatedly calls either diff_addremove() or diff_change(), which
>>> appends diff_filepair() to the diff_queue[] structure. If you see
>>> an unexpanded tree on the index side, you should be able to pass
>>> that tree with the subtree you are comparing against to the tree-diff
>>> machinery to come up with a series of filepairs, and then tweak the
>>> pathnames of these filepairs (as such a two-tree comparison would be
>>> comparing two trees representing a single subdirectory of two different
>>> vintages) before adding them to the diff_queue[] you are collecting
>>> the index-vs-tree diff, for example.
>>
>> Good to know it seems my idea might be reasonable.
>
> I agree that this is reasonable. I just didn't look hard enough
> to find existing code for this, since I found traverse_trees and
> thought that _was_ the library for this.
This was surprisingly simple, since most of the complicated stuff
is built into diff_tree_oid() and its use of revs->diffopt. The
new patch works as shown below the cut-line.
I was incredibly suspicious of how quickly this came together,
but it passes all the tests I have for it (including Scalar
functional tests with the commit, checkout, and add integrations).
I'll send a new version with this patch tomorrow, as well as the
other recommended edits.
Thanks,
-Stolee
--- >8 ---
diff --git a/diff-lib.c b/diff-lib.c
index c2ac9250fe9..b631df89343 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -316,6 +316,13 @@ static int get_stat_data(const struct index_state *istate,
return 0;
}
+static void show_directory(struct rev_info *revs,
+ const struct cache_entry *new_dir,
+ int added)
+{
+ diff_tree_oid(NULL, &new_dir->oid, new_dir->name, &revs->diffopt);
+}
+
static void show_new_file(struct rev_info *revs,
const struct cache_entry *new_file,
int cached, int match_missing)
@@ -325,6 +332,11 @@ static void show_new_file(struct rev_info *revs,
unsigned dirty_submodule = 0;
struct index_state *istate = revs->diffopt.repo->index;
+ if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
+ show_directory(revs, new_file, /*added */ 1);
+ return;
+ }
+
/*
* New file in the index: it might actually be different in
* the working tree.
@@ -336,6 +348,15 @@ static void show_new_file(struct rev_info *revs,
diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
}
+static void show_modified_sparse_directory(struct rev_info *revs,
+ const struct cache_entry *old_entry,
+ const struct cache_entry *new_entry,
+ int report_missing,
+ int cached, int match_missing)
+{
+ diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
+}
+
static int show_modified(struct rev_info *revs,
const struct cache_entry *old_entry,
const struct cache_entry *new_entry,
@@ -347,6 +368,17 @@ static int show_modified(struct rev_info *revs,
unsigned dirty_submodule = 0;
struct index_state *istate = revs->diffopt.repo->index;
+ /*
+ * If both are sparse directory entries, then expand the
+ * modifications to the file level.
+ */
+ if (old_entry && new_entry &&
+ S_ISSPARSEDIR(old_entry->ce_mode) &&
+ S_ISSPARSEDIR(new_entry->ce_mode)) {
+ show_modified_sparse_directory(revs, old_entry, new_entry, report_missing, cached, match_missing);
+ return 0;
+ }
+
if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
&dirty_submodule, &revs->diffopt) < 0) {
if (report_missing)
