Merge branch 'jc/maint-combine-diff-pre-context' into maint

* jc/maint-combine-diff-pre-context:
  diff -c/--cc: do not include uninteresting deletion before leading context

combine-diff.c

@@ -84,6 +84,7 @@ struct sline {
 	/* bit 0 up to (N-1) are on if the parent has this line (i.e.
 	 * we did not change it).
 	 * bit N is used for "interesting" lines, including context.
+	 * bit (N+1) is used for "do not show deletion before this".
 	 */
 	unsigned long flag;
 	unsigned long *p_lno;
@@ -308,6 +309,7 @@ static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 {
 	unsigned long all_mask = (1UL<<num_parent) - 1;
 	unsigned long mark = (1UL<<num_parent);
+	unsigned long no_pre_delete = (2UL<<num_parent);
 	unsigned long i;
 
 	/* Two groups of interesting lines may have a short gap of
@@ -329,7 +331,7 @@ static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 
 		/* Paint a few lines before the first interesting line. */
 		while (j < i)
-			sline[j++].flag |= mark;
+			sline[j++].flag |= mark | no_pre_delete;
 
 	again:
 		/* we know up to i is to be included.  where does the
@@ -502,6 +504,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 		       int use_color)
 {
 	unsigned long mark = (1UL<<num_parent);
+	unsigned long no_pre_delete = (2UL<<num_parent);
 	int i;
 	unsigned long lno = 0;
 	const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
@@ -581,7 +584,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 			int j;
 			unsigned long p_mask;
 			sl = &sline[lno++];
-			ll = sl->lost_head;
+			ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 			while (ll) {
 				fputs(c_old, stdout);
 				for (j = 0; j < num_parent; j++) {