diff options
author | Jeff King <peff@peff.net> | 2016-08-31 01:05:38 -0400 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2016-08-31 09:59:53 -0700 |
commit | 3dbfe2b8ae94cbdae5f3d32581aedaa5510fdc87 (patch) | |
tree | 764f91156b2707cb6dc7c5a4cc4f8784203411bc /contrib/diff-highlight | |
parent | diff-highlight: add multi-byte tests (diff) | |
download | tgif-3dbfe2b8ae94cbdae5f3d32581aedaa5510fdc87.tar.xz |
diff-highlight: avoid highlighting combined diffs
The algorithm in diff-highlight only understands how to look
at two sides of a diff; it cannot correctly handle combined
diffs with multiple preimages. Often highlighting does not
trigger at all for these diffs because the line counts do
not match up. E.g., if we see:
- ours
-theirs
++resolved
we would not bother highlighting; it naively looks like a
single line went away, and then a separate hunk added
another single line.
But of course there are exceptions. E.g., if the other side
deleted the line, we might see:
- ours
++resolved
which looks like we dropped " ours" and added "+resolved".
This is only a small highlighting glitch (we highlight the
space and the "+" along with the content), but it's also the
tip of the iceberg. Even if we learned to find the true
content here (by noticing we are in a 3-way combined diff
and marking _two_ characters from the front of the line as
uninteresting), there are other more complicated cases where
we really do need to handle a 3-way hunk.
Let's just punt for now; we can recognize combined diffs by
the presence of extra "@" symbols in the hunk header, and
treat them as non-diff content.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'contrib/diff-highlight')
-rwxr-xr-x | contrib/diff-highlight/diff-highlight | 2 | ||||
-rwxr-xr-x | contrib/diff-highlight/t/t9400-diff-highlight.sh | 37 |
2 files changed, 38 insertions, 1 deletions
diff --git a/contrib/diff-highlight/diff-highlight b/contrib/diff-highlight/diff-highlight index 9280c88800..81bd8040e3 100755 --- a/contrib/diff-highlight/diff-highlight +++ b/contrib/diff-highlight/diff-highlight @@ -36,7 +36,7 @@ $SIG{PIPE} = 'DEFAULT'; while (<>) { if (!$in_hunk) { print; - $in_hunk = /^$GRAPH*$COLOR*\@/; + $in_hunk = /^$GRAPH*$COLOR*\@\@ /; } elsif (/^$GRAPH*$COLOR*-/) { push @removed, $_; diff --git a/contrib/diff-highlight/t/t9400-diff-highlight.sh b/contrib/diff-highlight/t/t9400-diff-highlight.sh index b0fe7cc8aa..3b43dbed74 100755 --- a/contrib/diff-highlight/t/t9400-diff-highlight.sh +++ b/contrib/diff-highlight/t/t9400-diff-highlight.sh @@ -256,4 +256,41 @@ test_expect_success 'diff-highlight works with the --graph option' ' test_cmp graph.exp graph.act ' +# Most combined diffs won't meet diff-highlight's line-number filter. So we +# create one here where one side drops a line and the other modifies it. That +# should result in a diff like: +# +# - modified content +# ++resolved content +# +# which naively looks like one side added "+resolved". +test_expect_success 'diff-highlight ignores combined diffs' ' + echo "content" >file && + git add file && + git commit -m base && + + >file && + git commit -am master && + + git checkout -b other HEAD^ && + echo "modified content" >file && + git commit -am other && + + test_must_fail git merge master && + echo "resolved content" >file && + git commit -am resolved && + + cat >expect <<-\EOF && + --- a/file + +++ b/file + @@@ -1,1 -1,0 +1,1 @@@ + - modified content + ++resolved content + EOF + + git show -c | "$DIFF_HIGHLIGHT" >actual.raw && + sed -n "/^---/,\$p" <actual.raw >actual && + test_cmp expect actual +' + test_done |