From: Phillip Wood Date: Tue, 04 Sep 2018 18:51:01 GMT Subject: Re: [PATCH] diff: fix --color-moved-ws=allow-indentation-change Message-ID: In-Reply-To: Hi Stefan On 04/09/2018 19:08, Stefan Beller wrote: > On Tue, Sep 4, 2018 at 6:53 AM Phillip Wood wrote: >> >> From: Phillip Wood >> >> If there is more than one potential moved block and the longest block >> is not the first element of the array of potential blocks then the >> block is cut short. With --color-moved=blocks this can leave moved >> lines unpainted if the shortened block does not meet the block length >> requirement. With --color-moved=zebra then in addition to the >> unpainted lines the moved color can change in the middle of a single >> block. >> >> Fix this by freeing the whitespace delta of the match we're discarding >> rather than the one we're keeping. >> >> Signed-off-by: Phillip Wood >> --- >> >> While I was working on this I spotted a couple of other issues I don't >> have time to fix myself at the moment, so I thought I mention them in >> case someone else wants to pick them up >> >> 1) I think there is a potential memory leak at the end of >> mark_color_as_moved(). If pmb_nr > 0 then the whitespace deltas >> need freeing before freeing pmb itself. >> >> 2) The documentation could be improved to explain that >> allow-indentation-change does not work with indentation that >> contains a mix of tabs and spaces and the motivation for that >> (python?) [I've got some code to add an option that supports that >> which I'll post when I've written some tests after 2.19 is >> released] >> >> diff.c | 11 ++++++----- >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/diff.c b/diff.c >> index 145cfbae5..4e8f725bb 100644 >> --- a/diff.c >> +++ b/diff.c >> @@ -968,8 +968,13 @@ static void pmb_advance_or_null_multi_match(struct diff_options *o, >> /* Carry the white space delta forward */ >> pmb[i]->next_line->wsd = pmb[i]->wsd; >> pmb[i] = pmb[i]->next_line; >> - } else >> + } else { >> + if (pmb[i]->wsd) { >> + free(pmb[i]->wsd->string); >> + FREE_AND_NULL(pmb[i]->wsd); >> + } >> pmb[i] = NULL; >> + } > > I agree on this hunk, as it will fix the mem leak in the case of > allow-indentation-change, wondering if we need the same in > pmb_advance_or_null as well (and anywhere where there is a > 'pmb[i] = NULL' assignment outside the swapping below.). I don't think we don't call pmb_advance_or_null() if we're using pmb[i]->wsd. I'm not sure if there are other sites that set 'pmb[i] = NULL' when pmb[i]->wsd has been allocated. > > >> } >> } >> >> @@ -990,10 +995,6 @@ static int shrink_potential_moved_blocks(struct moved_entry **pmb, >> >> if (lp < pmb_nr && rp > -1 && lp < rp) { >> pmb[lp] = pmb[rp]; >> - if (pmb[rp]->wsd) { >> - free(pmb[rp]->wsd->string); >> - FREE_AND_NULL(pmb[rp]->wsd); >> - } > > Eh, this makes sense, though I had to think about it for a > while as I was confused. By the first line in the condition we > also keep around the ->wsd pointer as is. Yes, it took me ages to work out that this is what was breaking the highlighting. Best Wishes Phillip > > Thanks! > Stefan >