[PATCH 1/2] line-log: fix crash when combined with pickaxe options
From: Michael Montalbo <mmontalbo@gmail.com>
queue_diffs() calls diffcore_std() to detect renames so that line-level history can follow files across renames. When pickaxe options are present on the command line (-G and -S to filter by text pattern, --find-object to filter by object identity), diffcore_std() also runs diffcore_pickaxe(), which may discard diff pairs that are relevant for rename detection. Losing those pairs breaks rename following.
Before a2bb801f6a (line-log: avoid unnecessary full tree diffs, 2019-08-21), diffcore_std() was only invoked when a rename was already suspected, so the pickaxe interference was unlikely in practice. That commit made the diffcore_std() call unconditional, and with filter_diffs_for_paths() now framing that call, a queue pruned by pickaxe violates filter_diffs_for_paths()'s expectation that diff pairs correspond to tracked paths, triggering an assertion failure.
Fix this by calling diffcore_rename() directly instead of diffcore_std(). The line-log machinery only needs rename detection from this call site; the other stages run by diffcore_std() (pickaxe, order, break/rewrite) are unnecessary here.
Note that this only fixes the crash. The -G, -S, and --find-object options still have no effect on -L output because line-log uses its own commit-filtering logic that bypasses the normal pickaxe pipeline. Add tests that verify the crash is fixed and mark the silent-ignore behavior as known breakage for all three options.
Reported-by: Matthew Hughes <matthewhughes934@gmail.com>
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
---
line-log.c | 8 +++++++-
t/t4211-line-log.sh | 49 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+), 1 deletion(-)
Show changes to 2 files +56 −1
line-log.c, t/t4211-line-log.sh
diff --git a/line-log.c b/line-log.c
index 8bd422148d..8a404f5c22 100644
--- a/line-log.c
+++ b/line-log.c
@@ -865,7 +865,13 @@ static void queue_diffs(struct line_log_data *range,
diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
filter_diffs_for_paths(range, 1);
- diffcore_std(opt);
+ /*
+ * Call diffcore_rename() directly, as only rename
+ * detection is needed. diffcore_std() would also run
+ * pickaxe, which may discard pairs needed for rename
+ * detection and break rename following.
+ */
+ diffcore_rename(opt);
filter_diffs_for_paths(range, 0);
}
move_diff_queue(queue, &diff_queued_diff);
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 0a7c3ca42f..7acc38f72d 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -367,4 +367,53 @@ test_expect_success 'show line-log with graph' '
test_cmp expect actual
'
+test_expect_success 'setup for -L with -G/-S/--find-object and a merge with rename' '
+ git checkout --orphan pickaxe-rename &&
+ git reset --hard &&
+
+ echo content >file &&
+ git add file &&
+ git commit -m "add file" &&
+
+ git checkout -b pickaxe-rename-side &&
+ git mv file renamed-file &&
+ git commit -m "rename file" &&
+
+ git checkout pickaxe-rename &&
+ git commit --allow-empty -m "diverge" &&
+ git merge --no-edit pickaxe-rename-side &&
+
+ git mv renamed-file file &&
+ git commit -m "rename back"
+'
+
+test_expect_success '-L -G does not crash with merge and rename' '
+ git log --format="%s" --no-patch -L 1,1:file -G "." >actual
+'
+
+test_expect_success '-L -S does not crash with merge and rename' '
+ git log --format="%s" --no-patch -L 1,1:file -S content >actual
+'
+
+test_expect_success '-L --find-object does not crash with merge and rename' '
+ git log --format="%s" --no-patch -L 1,1:file \
+ --find-object=$(git rev-parse HEAD:file) >actual
+'
+
+test_expect_failure '-L -G should filter commits by pattern' '
+ git log --format="%s" --no-patch -L 1,1:file -G "nomatch" >actual &&
+ test_must_be_empty actual
+'
+
+test_expect_failure '-L -S should filter commits by pattern' '
+ git log --format="%s" --no-patch -L 1,1:file -S "nomatch" >actual &&
+ test_must_be_empty actual
+'
+
+test_expect_failure '-L --find-object should filter commits by object' '
+ git log --format="%s" --no-patch -L 1,1:file \
+ --find-object=$ZERO_OID >actual &&
+ test_must_be_empty actual
+'
+
test_done
--
gitgitgadget
Michael Montalbo via GitGitGadget