From ee95ec5d58d536243966de6ee810d345074b755e Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Sun, 17 Feb 2008 19:07:40 +0000 Subject: [PATCH] xdl_merge(): introduce XDL_MERGE_ZEALOUS_ALNUM When a merge conflicts, there are often common lines that are not really common, such as empty lines or lines containing a single curly bracket. With XDL_MERGE_ZEALOUS_ALNUM, we use the following heuristics: when a hunk does not contain any letters or digits, it is treated as conflicting. In other words, a conflict which used to look like this: <<<<<<< a = 1; ======= output(); >>>>>>> } } } <<<<<<< output(); ======= b = 1; >>>>>>> will look like this with ZEALOUS_ALNUM: <<<<<<< a = 1; } } } output(); ======= output(); } } } b = 1; >>>>>>> To demonstrate this, git-merge-file has been switched from XDL_MERGE_ZEALOUS to XDL_MERGE_ZEALOUS_ALNUM. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- builtin-merge-file.c | 2 +- t/t6023-merge-file.sh | 10 ++++++++++ xdiff/xdiff.h | 1 + xdiff/xmerge.c | 31 +++++++++++++++++++++++++++---- 4 files changed, 39 insertions(+), 5 deletions(-) diff --git a/builtin-merge-file.c b/builtin-merge-file.c index 58deb62ac..adce6d463 100644 --- a/builtin-merge-file.c +++ b/builtin-merge-file.c @@ -46,7 +46,7 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix) } ret = xdl_merge(mmfs + 1, mmfs + 0, names[0], mmfs + 2, names[2], - &xpp, XDL_MERGE_ZEALOUS, &result); + &xpp, XDL_MERGE_ZEALOUS_ALNUM, &result); for (i = 0; i < 3; i++) free(mmfs[i].ptr); diff --git a/t/t6023-merge-file.sh b/t/t6023-merge-file.sh index 869e8d559..79dc58b2c 100755 --- a/t/t6023-merge-file.sh +++ b/t/t6023-merge-file.sh @@ -149,4 +149,14 @@ test_expect_success 'MERGE_ZEALOUS simplifies non-conflicts' ' ' +sed -e 's/deerit./&\n\n\n\n/' -e "s/locavit,/locavit;/" < new6.txt > new8.txt +sed -e 's/deerit./&\n\n\n\n/' -e "s/locavit,/locavit --/" < new7.txt > new9.txt + +test_expect_success 'ZEALOUS_ALNUM' ' + + ! git merge-file -p new8.txt new5.txt new9.txt > merge.out && + test 1 = $(grep ======= < merge.out | wc -l) + +' + test_done diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h index c00ddaa6e..413082e1f 100644 --- a/xdiff/xdiff.h +++ b/xdiff/xdiff.h @@ -53,6 +53,7 @@ extern "C" { #define XDL_MERGE_MINIMAL 0 #define XDL_MERGE_EAGER 1 #define XDL_MERGE_ZEALOUS 2 +#define XDL_MERGE_ZEALOUS_ALNUM 3 typedef struct s_mmfile { char *ptr; diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c index ecbdae502..82b3573e7 100644 --- a/xdiff/xmerge.c +++ b/xdiff/xmerge.c @@ -248,6 +248,23 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m, return 0; } +static int line_contains_alnum(const char *ptr, long size) +{ + while (size--) + if (isalnum(*(ptr++))) + return 1; + return 0; +} + +static int lines_contain_alnum(xdfenv_t *xe, int i, int chg) +{ + for (; chg; chg--, i++) + if (line_contains_alnum(xe->xdf2.recs[i]->ptr, + xe->xdf2.recs[i]->size)) + return 1; + return 0; +} + /* * This function merges m and m->next, marking everything between those hunks * as conflicting, too. @@ -266,7 +283,8 @@ static void xdl_merge_two_conflicts(xdmerge_t *m) * it appears simpler -- because it takes up less (or as many) lines -- * if the lines are moved into the conflicts. */ -static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m) +static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m, + int simplify_if_no_alnum) { int result = 0; @@ -282,9 +300,12 @@ static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m) begin = m->i1 + m->chg1; end = next_m->i1; - if (m->mode != 0 || next_m->mode != 0 || end - begin > 3) + if (m->mode != 0 || next_m->mode != 0 || + (end - begin > 3 && + (!simplify_if_no_alnum || + lines_contain_alnum(xe1, begin, end - begin)))) { m = next_m; - else { + } else { result++; xdl_merge_two_conflicts(m); } @@ -295,6 +316,8 @@ static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m) * level == 0: mark all overlapping changes as conflict * level == 1: mark overlapping changes as conflict only if not identical * level == 2: analyze non-identical changes for minimal conflict set + * level == 3: analyze non-identical changes for minimal conflict set, but + * treat hunks not containing any letter or number as conflicting * * returns < 0 on error, == 0 for no conflicts, else number of conflicts */ @@ -400,7 +423,7 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1, /* refine conflicts */ if (level > 1 && (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 || - xdl_simplify_non_conflicts(xe1, changes) < 0)) { + xdl_simplify_non_conflicts(xe1, changes, level > 2) < 0)) { xdl_cleanup_merge(changes); return -1; } -- 2.30.2