From fd4b1d2193640009c9303daa784691fc5e102018 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Thu, 2 Feb 2006 01:28:08 -0800 Subject: [PATCH] combine-diff: add safety check to --cc. The earlier change implemented "only two version" check but without checking if the change rewrites from all the parents. This implements a check to make sure that a change introduced by the merge from all the parents is caught to be interesting. Signed-off-by: Junio C Hamano --- combine-diff.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/combine-diff.c b/combine-diff.c index 44931b2a89..8f295c89d0 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -397,7 +397,23 @@ static int make_hunks(struct sline *sline, unsigned long cnt, hunk_end = j; /* [i..hunk_end) are interesting. Now is it really - * interesting? + * interesting? We check if there are only two versions + * and the result matches one of them. That is, we look + * at: + * (+) line, which records lines added to which parents; + * this line appears in the result. + * (-) line, which records from what parents the line + * was removed; this line does not appear in the result. + * then check the set of parents the result has difference + * from, from all lines. If there are lines that has + * different set of parents that the result has differences + * from, that means we have more than two versions. + * + * Even when we have only two versions, if the result does + * not match any of the parents, the it should be considered + * interesting. In such a case, we would have all '+' line. + * After passing the above "two versions" test, that would + * appear as "the same set of parents" to be "all parents". */ same_diff = 0; has_interesting = 0; @@ -429,7 +445,7 @@ static int make_hunks(struct sline *sline, unsigned long cnt, } } - if (!has_interesting) { + if (!has_interesting && same_diff != all_mask) { /* This hunk is not that interesting after all */ for (j = hunk_begin; j < hunk_end; j++) sline[j].flag &= ~mark;