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 <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Johannes Schindelin committed
Feb 17, 2008 at 19:07 UTC
ee95ec5d58d536243966de6ee810d345074b755e
4 files changed
+39
-5
builtin-merge-file.c
+1
-1
@@ -46,7 +46,7 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
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}
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ret = xdl_merge(mmfs + 1, mmfs + 0, names[0], mmfs + 2, names[2],
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- &xpp, XDL_MERGE_ZEALOUS, &result);
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+ &xpp, XDL_MERGE_ZEALOUS_ALNUM, &result);
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for (i = 0; i < 3; i++)
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free(mmfs[i].ptr);
t/t6023-merge-file.sh
+10
@@ -149,4 +149,14 @@ test_expect_success 'MERGE_ZEALOUS simplifies non-conflicts' '
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'
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+sed -e 's/deerit./&\n\n\n\n/' -e "s/locavit,/locavit;/" < new6.txt > new8.txt
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+sed -e 's/deerit./&\n\n\n\n/' -e "s/locavit,/locavit --/" < new7.txt > new9.txt
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+
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+test_expect_success 'ZEALOUS_ALNUM' '
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+
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+ ! git merge-file -p new8.txt new5.txt new9.txt > merge.out &&
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+ test 1 = $(grep ======= < merge.out | wc -l)
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+
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+'
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+
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test_done
xdiff/xdiff.h
+1
@@ -53,6 +53,7 @@ extern "C" {
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#define XDL_MERGE_MINIMAL 0
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#define XDL_MERGE_EAGER 1
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#define XDL_MERGE_ZEALOUS 2
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+#define XDL_MERGE_ZEALOUS_ALNUM 3
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typedef struct s_mmfile {
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char *ptr;
xdiff/xmerge.c
+27
-4
@@ -248,6 +248,23 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
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return 0;
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}
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+static int line_contains_alnum(const char *ptr, long size)
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+{
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+ while (size--)
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+ if (isalnum(*(ptr++)))
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+ return 1;
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+ return 0;
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+}
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+
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+static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
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+{
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+ for (; chg; chg--, i++)
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+ if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
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+ xe->xdf2.recs[i]->size))
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+ return 1;
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+ return 0;
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+}
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+
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/*
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* This function merges m and m->next, marking everything between those hunks
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* as conflicting, too.
@@ -266,7 +283,8 @@ static void xdl_merge_two_conflicts(xdmerge_t *m)
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* it appears simpler -- because it takes up less (or as many) lines --
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* if the lines are moved into the conflicts.
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*/
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-static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m)
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+static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
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+ int simplify_if_no_alnum)
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{
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int result = 0;
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@@ -282,9 +300,12 @@ static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m)
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begin = m->i1 + m->chg1;
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end = next_m->i1;
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- if (m->mode != 0 || next_m->mode != 0 || end - begin > 3)
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+ if (m->mode != 0 || next_m->mode != 0 ||
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+ (end - begin > 3 &&
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+ (!simplify_if_no_alnum ||
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+ lines_contain_alnum(xe1, begin, end - begin)))) {
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m = next_m;
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- else {
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+ } else {
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result++;
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xdl_merge_two_conflicts(m);
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}
@@ -295,6 +316,8 @@ static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m)
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* level == 0: mark all overlapping changes as conflict
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* level == 1: mark overlapping changes as conflict only if not identical
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* level == 2: analyze non-identical changes for minimal conflict set
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+ * level == 3: analyze non-identical changes for minimal conflict set, but
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+ * treat hunks not containing any letter or number as conflicting
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*
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* returns < 0 on error, == 0 for no conflicts, else number of conflicts
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*/
@@ -400,7 +423,7 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
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/* refine conflicts */
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if (level > 1 &&
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(xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
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- xdl_simplify_non_conflicts(xe1, changes) < 0)) {
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+ xdl_simplify_non_conflicts(xe1, changes, level > 2) < 0)) {
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xdl_cleanup_merge(changes);
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return -1;
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}