From 98e6da8a360b77af2924e8056fd951013835699b Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 5 Dec 2006 22:15:35 +0100 Subject: [PATCH] xdl_merge(): fix and simplify conflict handling Suppose you have changes in new1 to the original lines 10-20, and changes in new2 to the original lines 15-25, then the changes to 10-25 conflict. But it is possible that the next changes in new1 still overlap with this change to new2. So, in the next iteration we have to look at the same change to new2 again. The old code tried to be a bit too clever. The new code is shorter and more to the point: do not fiddle with the ranges at all. Also, xdl_append_merge() tries harder to combine conflicts. This is necessary, because with the above simplification, some conflicts would not be recognized as conflicts otherwise: In the above scenario, it is possible that there is no other change to new1. Absent the combine logic, the change in new2 would be recorded _again_, but as a non-conflict. Signed-off-by: Johannes Schindelin --- xdiff/xmerge.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c index 1fe7a1b06..352207e51 100644 --- a/xdiff/xmerge.c +++ b/xdiff/xmerge.c @@ -38,8 +38,9 @@ static int xdl_append_merge(xdmerge_t **merge, int mode, long i1, long chg1, long i2, long chg2) { xdmerge_t *m = *merge; - if (m && mode == m->mode && - (i1 == m->i1 + m->chg1 || i2 == m->i2 + m->chg2)) { + if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) { + if (mode != m->mode) + m->mode = 0; m->chg1 = i1 + chg1 - m->i1; m->chg2 = i2 + chg2 - m->i2; } else { @@ -313,22 +314,10 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1, i1 = xscr1->i1 + xscr1->chg1; i2 = xscr2->i1 + xscr2->chg1; - if (i1 > i2) { - xscr1->chg1 -= i1 - i2; - xscr1->i1 = i2; - xscr1->i2 += xscr1->chg2; - xscr1->chg2 = 0; + if (i1 >= i2) xscr2 = xscr2->next; - } else if (i2 > i1) { - xscr2->chg1 -= i2 - i1; - xscr2->i1 = i1; - xscr2->i2 += xscr2->chg2; - xscr2->chg2 = 0; - xscr1 = xscr1->next; - } else { + if (i2 >= i1) xscr1 = xscr1->next; - xscr2 = xscr2->next; - } } while (xscr1) { if (!changes) -- 2.30.2