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Diffstat (limited to 'xdiff/xemit.c')
-rw-r--r--xdiff/xemit.c49
1 files changed, 43 insertions, 6 deletions
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index d11dbf9f13..4d8645867e 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -56,16 +56,51 @@ static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *
/*
* Starting at the passed change atom, find the latest change atom to be included
* inside the differential hunk according to the specified configuration.
+ * Also advance xscr if the first changes must be discarded.
*/
-xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
- xdchange_t *xch, *xchp;
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
+{
+ xdchange_t *xch, *xchp, *lxch;
long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
+ long max_ignorable = xecfg->ctxlen;
+ unsigned long ignored = 0; /* number of ignored blank lines */
+
+ /* remove ignorable changes that are too far before other changes */
+ for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
+ xch = xchp->next;
+
+ if (xch == NULL ||
+ xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
+ *xscr = xch;
+ }
+
+ if (*xscr == NULL)
+ return NULL;
+
+ lxch = *xscr;
- for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
- if (xch->i1 - (xchp->i1 + xchp->chg1) > max_common)
+ for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
+ long distance = xch->i1 - (xchp->i1 + xchp->chg1);
+ if (distance > max_common)
break;
- return xchp;
+ if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
+ lxch = xch;
+ ignored = 0;
+ } else if (distance < max_ignorable && xch->ignore) {
+ ignored += xch->chg2;
+ } else if (lxch != xchp &&
+ xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) {
+ break;
+ } else if (!xch->ignore) {
+ lxch = xch;
+ ignored = 0;
+ } else {
+ ignored += xch->chg2;
+ }
+ }
+
+ return lxch;
}
@@ -139,7 +174,9 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
return xdl_emit_common(xe, xscr, ecb, xecfg);
for (xch = xscr; xch; xch = xche->next) {
- xche = xdl_get_hunk(xch, xecfg);
+ xche = xdl_get_hunk(&xch, xecfg);
+ if (!xch)
+ break;
s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);