"git diff -c -p" was not showing a deleted line from a hunk when
another hunk immediately begins where the earlier one ends.
* mk/combine-diff-context-horizon-fix:
combine-diff.c: Fix output when changes are exactly 3 lines apart
When a deletion is followed by exactly 3 (or whatever the number of
context lines) unchanged lines, followed by another change, the combined
diff output would hide the first deletion, resulting in a malformed
diff.
This happened because the 3 lines before each change are painted
interesting, but also marked as no_pre_delete to prevent showing deletes
that were previously marked as uninteresting. This behaviour was
introduced in c86fbe53 (diff -c/--cc: do not include uninteresting
deletion before leading context). However, as a side effect, this could
also mark deletes that were already interesting as no_pre_delete. This
would happen only if the delete was exactly 3 lines away from the next
change, since lines farther away would not be touched by the "paint
three lines before the change" code and lines closer would be painted
by the "merge two adjacent hunks" code instead, which does not set the
no_pre_delete flag.
This commit fixes this problem by only setting the no_pre_delete flag
for changes that were previously uninteresting.
Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This replaces the greedy implementation to coalesce lost lines by using
dynamic programming to find the Longest Common Subsequence.
The O(n²) time complexity is obviously bigger than previous
implementation but it can produce shorter diff results (and most likely
easier to read).
List of lost lines is now doubly-linked because we reverse-read it when
reading the direction matrix.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The combined diff --cc output does not honor options to ignore
whitespace changes (-b, -w, and --ignore-space-at-eol).
Correct this by passing diff flags to diff engine, so that combined
diff behaves as normal diff does with spaces, and by coalescing
lines that are removed from both (or more) parents, honoring the
same rule to ignore whitespace changes.
With this change, a conflict-less merge done using a ignore-*
strategy option will not show any conflict if shown in combined-diff
using the same option.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Consider an evil merge of two commits A and B, both of which have a
file 'foo', but the merge result does not have that file.
The combined-diff code learned in 4462731 (combine-diff: do not punt
on removed or added files., 2006-02-06) to concisely show only the
removal, since that is the evil part and the previous contents are
presumably uninteresting.
However, to diagnose an empty merge result, it overloaded the variable
that holds the file's length. This means that the check also triggers
for truncated files. Consequently, such files were not shown in the
diff at all despite the merge being clearly evil.
Fix this by adding a new variable that distinguishes whether the file
was deleted (which is the case 4462731 handled) or truncated. In the
truncated case, we show the full combined diff again, which is rather
spammy but at least does not hide the evilness.
Reported-by: David Martínez Martí <desarrollo@gestiweb.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"diff --cc" output t4038 tests was fixed by b810cbb (diff --cc: a lost
line at the beginning of the file is shown incorrectly, 2009-07-22), which
was actually the commit that introduced this test..
An error in "git merge -s resolve" t6035 tests was fixed by 730f728
(unpack-trees.c: look ahead in the index, 2009-09-20).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When combine-diff inspected the diff from one parent to the merge result,
it misinterpreted a header in the form @@ -l,k +0,0 @@.
This hunk header means that K lines were removed from the beginning of the
file, so the lost lines must be queued to the sline that represents the
first line of the merge result, but we incremented our pointer incorrectly
and ended up queuing it to the second line, which in turn made the lossage
appear _after_ the first line.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
