X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=combine-diff.c;h=210ffcbce38bf1155c6e9b054e0950ee07c979fe;hb=04fe2a1706b4bd71b604bfe7d7295064440872cf;hp=062ed8a7bfda9e84a91597232e61f7c62d877459;hpb=d8f4790e6fe7a9d94468ea83d1370643604d43e5;p=git.git

diff --git a/combine-diff.c b/combine-diff.c
index 062ed8a7..210ffcbc 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -4,14 +4,6 @@
 #include "diffcore.h"
 #include "quote.h"
 
-struct path_list {
-	struct path_list *next;
-	int len;
-	char *path;
-	unsigned char sha1[20];
-	unsigned char parent_sha1[FLEX_ARRAY][20];
-};
-
 static int uninteresting(struct diff_filepair *p)
 {
 	if (diff_unmodified_pair(p))
@@ -21,15 +13,14 @@ static int uninteresting(struct diff_filepair *p)
 	return 0;
 }
 
-static struct path_list *intersect_paths(struct path_list *curr,
-					 int n, int num_parent)
+static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
-	struct path_list *p;
+	struct combine_diff_path *p;
 	int i;
 
 	if (!n) {
-		struct path_list *list = NULL, *tail = NULL;
+		struct combine_diff_path *list = NULL, **tail = &list;
 		for (i = 0; i < q->nr; i++) {
 			int len;
 			const char *path;
@@ -46,12 +37,8 @@ static struct path_list *intersect_paths(struct path_list *curr,
 			p->next = NULL;
 			memcpy(p->sha1, q->queue[i]->two->sha1, 20);
 			memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
-			if (!tail)
-				list = tail = p;
-			else {
-				tail->next = p;
-				p = tail;
-			}
+			*tail = p;
+			tail = &p->next;
 		}
 		return list;
 	}
@@ -81,6 +68,7 @@ static struct path_list *intersect_paths(struct path_list *curr,
 	return curr;
 }
 
+/* Lines lost from parent */
 struct lline {
 	struct lline *next;
 	int len;
@@ -88,11 +76,17 @@ struct lline {
 	char line[FLEX_ARRAY];
 };
 
+/* Lines surviving in the merge result */
 struct sline {
 	struct lline *lost_head, **lost_tail;
 	char *bol;
 	int len;
+	/* 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.
+	 */
 	unsigned long flag;
+	unsigned long *p_lno;
 };
 
 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
@@ -212,22 +206,19 @@ static void append_lost(struct sline *sline, int n, const char *line)
 	lline->parent_map = this_mask;
 	memcpy(lline->line, line, len);
 	lline->line[len] = 0;
-	if (sline->lost_head)
-		*(sline->lost_tail) = lline;
-	else
-		sline->lost_head = lline;
+	*sline->lost_tail = lline;
 	sline->lost_tail = &lline->next;
 }
 
 static void combine_diff(const unsigned char *parent, const char *ourtmp,
-			 struct sline *sline, int cnt, int n)
+			 struct sline *sline, int cnt, int n, int num_parent)
 {
 	FILE *in;
 	char parent_tmp[TMPPATHLEN];
 	char cmd[TMPPATHLEN * 2 + 1024];
 	char line[MAXLINELEN];
-	unsigned int lno, ob, on, nb, nn;
-	unsigned long pmask = ~(1UL << n);
+	unsigned int lno, ob, on, nb, nn, p_lno;
+	unsigned long nmask = (1UL << n);
 	struct sline *lost_bucket = NULL;
 
 	write_temp_blob(parent_tmp, parent);
@@ -235,7 +226,7 @@ static void combine_diff(const unsigned char *parent, const char *ourtmp,
 		parent_tmp, ourtmp);
 	in = popen(cmd, "r");
 	if (!in)
-		return;
+		die("cannot spawn %s", cmd);
 
 	lno = 1;
 	while (fgets(line, sizeof(line), in) != NULL) {
@@ -245,29 +236,64 @@ static void combine_diff(const unsigned char *parent, const char *ourtmp,
 					      &ob, &on, &nb, &nn))
 				break;
 			lno = nb;
-			if (!nb) {
+			if (!nb)
 				/* @@ -1,2 +0,0 @@ to remove the
 				 * first two lines...
 				 */
 				nb = 1;
-			}
-			lost_bucket = &sline[nb-1]; /* sline is 0 based */
+			if (nn == 0)
+				/* @@ -X,Y +N,0 @@ removed Y lines
+				 * that would have come *after* line N
+				 * in the result.  Our lost buckets hang
+				 * to the line after the removed lines,
+				 */
+				lost_bucket = &sline[nb];
+			else
+				lost_bucket = &sline[nb-1];
+			if (!sline[nb-1].p_lno)
+				sline[nb-1].p_lno =
+					xcalloc(num_parent,
+						sizeof(unsigned long));
+			sline[nb-1].p_lno[n] = ob;
 			continue;
 		}
 		if (!lost_bucket)
-			continue;
+			continue; /* not in any hunk yet */
 		switch (line[0]) {
 		case '-':
 			append_lost(lost_bucket, n, line+1);
 			break;
 		case '+':
-			sline[lno-1].flag &= pmask;
+			sline[lno-1].flag |= nmask;
 			lno++;
 			break;
 		}
 	}
 	fclose(in);
 	unlink(parent_tmp);
+
+	/* Assign line numbers for this parent.
+	 *
+	 * sline[lno].p_lno[n] records the first line number
+	 * (counting from 1) for parent N if the final hunk display
+	 * started by showing sline[lno] (possibly showing the lost
+	 * lines attached to it first).
+	 */
+	for (lno = 0,  p_lno = 1; lno < cnt; lno++) {
+		struct lline *ll;
+		sline[lno].p_lno[n] = p_lno;
+
+		/* How many lines would this sline advance the p_lno? */
+		ll = sline[lno].lost_head;
+		while (ll) {
+			if (ll->parent_map & nmask)
+				p_lno++; /* '-' means parent had it */
+			ll = ll->next;
+		}
+		if (!(sline[lno].flag & nmask))
+			p_lno++; /* no '+' means parent had it */
+	}
+	sline[lno].p_lno[n] = p_lno; /* trailer */
 }
 
 static unsigned long context = 3;
@@ -275,97 +301,241 @@ static char combine_marker = '@';
 
 static int interesting(struct sline *sline, unsigned long all_mask)
 {
-	return ((sline->flag & all_mask) != all_mask || sline->lost_head);
+	/* If some parents lost lines here, or if we have added to
+	 * some parent, it is interesting.
+	 */
+	return ((sline->flag & all_mask) || sline->lost_head);
 }
 
-static unsigned long line_diff_parents(struct sline *sline, unsigned long all_mask)
+static unsigned long adjust_hunk_tail(struct sline *sline,
+				      unsigned long all_mask,
+				      unsigned long hunk_begin,
+				      unsigned long i)
 {
-	/*
-	 * Look at the line and see from which parents we have difference.
-	 * Lower bits of sline->flag records if the parent had this line,
-	 * so XOR with all_mask gives us on-bits for parents we have
-	 * differences with.
+	/* i points at the first uninteresting line.  If the last line
+	 * of the hunk was interesting only because it has some
+	 * deletion, then it is not all that interesting for the
+	 * purpose of giving trailing context lines.  This is because
+	 * we output '-' line and then unmodified sline[i-1] itself in
+	 * that case which gives us one extra context line.
 	 */
-	unsigned long parents = (sline->flag ^ all_mask);
-	if (sline->lost_head) {
-		struct lline *ll;
-		for (ll = sline->lost_head; ll; ll = ll->next)
-			parents |= ll->parent_map;
-	}
-	return parents & all_mask;
+	if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
+		i--;
+	return i;
 }
 
-static void make_hunks(struct sline *sline, unsigned long cnt,
-		       int num_parent, int dense)
+static unsigned long find_next(struct sline *sline,
+			       unsigned long mark,
+			       unsigned long i,
+			       unsigned long cnt,
+			       int uninteresting)
+{
+	/* We have examined up to i-1 and are about to look at i.
+	 * Find next interesting or uninteresting line.  Here,
+	 * "interesting" does not mean interesting(), but marked by
+	 * the give_context() function below (i.e. it includes context
+	 * lines that are not interesting to interesting() function
+	 * that are surrounded by interesting() ones.
+	 */
+	while (i < cnt)
+		if (uninteresting
+		    ? !(sline[i].flag & mark)
+		    : (sline[i].flag & mark))
+			return i;
+		else
+			i++;
+	return cnt;
+}
+
+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 i;
 
-	i = 0;
+	/* Two groups of interesting lines may have a short gap of
+	 * unintersting lines.  Connect such groups to give them a
+	 * bit of context.
+	 *
+	 * We first start from what the interesting() function says,
+	 * and mark them with "mark", and paint context lines with the
+	 * mark.  So interesting() would still say false for such context
+	 * lines but they are treated as "interesting" in the end.
+	 */
+	i = find_next(sline, mark, 0, cnt, 0);
+	if (cnt <= i)
+		return 0;
+
 	while (i < cnt) {
-		if (interesting(&sline[i], all_mask)) {
-			unsigned long j = (context < i) ? i - context : 0;
-			while (j <= i)
+		unsigned long j = (context < i) ? (i - context) : 0;
+		unsigned long k;
+
+		/* Paint a few lines before the first interesting line. */
+		while (j < i)
+			sline[j++].flag |= mark;
+
+	again:
+		/* we know up to i is to be included.  where does the
+		 * next uninteresting one start?
+		 */
+		j = find_next(sline, mark, i, cnt, 1);
+		if (cnt <= j)
+			break; /* the rest are all interesting */
+
+		/* lookahead context lines */
+		k = find_next(sline, mark, j, cnt, 0);
+		j = adjust_hunk_tail(sline, all_mask, i, j);
+
+		if (k < j + context) {
+			/* k is interesting and [j,k) are not, but
+			 * paint them interesting because the gap is small.
+			 */
+			while (j < k)
 				sline[j++].flag |= mark;
-			while (++i < cnt) {
-				if (!interesting(&sline[i], all_mask))
-					break;
-				sline[i].flag |= mark;
-			}
-			j = (i + context < cnt) ? i + context : cnt;
-			while (i < j)
-				sline[i++].flag |= mark;
-			continue;
+			i = k;
+			goto again;
 		}
-		i++;
+
+		/* j is the first uninteresting line and there is
+		 * no overlap beyond it within context lines.  Paint
+		 * the trailing edge a bit.
+		 */
+		i = k;
+		k = (j + context < cnt) ? j + context : cnt;
+		while (j < k)
+			sline[j++].flag |= mark;
+	}
+	return 1;
+}
+
+static int make_hunks(struct sline *sline, unsigned long cnt,
+		       int num_parent, int dense)
+{
+	unsigned long all_mask = (1UL<<num_parent) - 1;
+	unsigned long mark = (1UL<<num_parent);
+	unsigned long i;
+	int has_interesting = 0;
+
+	for (i = 0; i < cnt; i++) {
+		if (interesting(&sline[i], all_mask))
+			sline[i].flag |= mark;
+		else
+			sline[i].flag &= ~mark;
 	}
 	if (!dense)
-		return;
+		return give_context(sline, cnt, num_parent);
 
-	/* Look at each hunk, and if it contains changes from only
-	 * one parent, mark that uninteresting.
+	/* Look at each hunk, and if we have changes from only one
+	 * parent, or the changes are the same from all but one
+	 * parent, mark that uninteresting.
 	 */
 	i = 0;
 	while (i < cnt) {
-		int j, hunk_end, diffs;
-		unsigned long parents;
+		unsigned long j, hunk_begin, hunk_end;
+		unsigned long same_diff;
 		while (i < cnt && !(sline[i].flag & mark))
 			i++;
 		if (cnt <= i)
 			break; /* No more interesting hunks */
-		for (hunk_end = i + 1; hunk_end < cnt; hunk_end++)
-			if (!(sline[hunk_end].flag & mark))
-				break;
-		/* [i..hunk_end) are interesting.  Now is it from
-		 * only one parent?
-		 * If lost lines are only from one parent and
-		 * remaining lines existed in parents other than
-		 * that parent, then the hunk is not that interesting.
+		hunk_begin = i;
+		for (j = i + 1; j < cnt; j++) {
+			if (!(sline[j].flag & mark)) {
+				/* Look beyond the end to see if there
+				 * is an interesting line after this
+				 * hunk within context span.
+				 */
+				unsigned long la; /* lookahead */
+				int contin = 0;
+				la = adjust_hunk_tail(sline, all_mask,
+						     hunk_begin, j);
+				la = (la + context < cnt) ?
+					(la + context) : cnt;
+				while (j <= --la) {
+					if (sline[la].flag & mark) {
+						contin = 1;
+						break;
+					}
+				}
+				if (!contin)
+					break;
+				j = la;
+			}
+		}
+		hunk_end = j;
+
+		/* [i..hunk_end) are interesting.  Now is it really
+		 * interesting?  We check if there are only two versions
+		 * and the result matches one of them.  That is, we look
+		 * at:
+		 *   (+) line, which records lines added to which parents;
+		 *       this line appears in the result.
+		 *   (-) line, which records from what parents the line
+		 *       was removed; this line does not appear in the result.
+		 * then check the set of parents the result has difference
+		 * from, from all lines.  If there are lines that has
+		 * different set of parents that the result has differences
+		 * from, that means we have more than two versions.
+		 *
+		 * Even when we have only two versions, if the result does
+		 * not match any of the parents, the it should be considered
+		 * interesting.  In such a case, we would have all '+' line.
+		 * After passing the above "two versions" test, that would
+		 * appear as "the same set of parents" to be "all parents".
 		 */
-		parents = 0;
-		diffs = 0;
-		for (j = i; j < hunk_end; j++)
-			parents |= line_diff_parents(sline + j, all_mask);
-		/* Now, how many bits from [0..num_parent) are on? */
-		for (j = 0; j < num_parent; j++) {
-			if (parents & (1UL<<j))
-				diffs++;
+		same_diff = 0;
+		has_interesting = 0;
+		for (j = i; j < hunk_end && !has_interesting; j++) {
+			unsigned long this_diff = sline[j].flag & all_mask;
+			struct lline *ll = sline[j].lost_head;
+			if (this_diff) {
+				/* This has some changes.  Is it the
+				 * same as others?
+				 */
+				if (!same_diff)
+					same_diff = this_diff;
+				else if (same_diff != this_diff) {
+					has_interesting = 1;
+					break;
+				}
+			}
+			while (ll && !has_interesting) {
+				/* Lost this line from these parents;
+				 * who are they?  Are they the same?
+				 */
+				this_diff = ll->parent_map;
+				if (!same_diff)
+					same_diff = this_diff;
+				else if (same_diff != this_diff) {
+					has_interesting = 1;
+				}
+				ll = ll->next;
+			}
 		}
-		if (diffs < 2) {
+
+		if (!has_interesting && same_diff != all_mask) {
 			/* This hunk is not that interesting after all */
-			for (j = i; j < hunk_end; j++)
+			for (j = hunk_begin; j < hunk_end; j++)
 				sline[j].flag &= ~mark;
 		}
 		i = hunk_end;
 	}
+
+	has_interesting = give_context(sline, cnt, num_parent);
+	return has_interesting;
 }
 
-static void dump_sline(struct sline *sline, int cnt, int num_parent)
+static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, unsigned long cnt, int n)
+{
+	l0 = sline[l0].p_lno[n];
+	l1 = sline[l1].p_lno[n];
+	printf(" -%lu,%lu", l0, l1-l0);
+}
+
+static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent)
 {
 	unsigned long mark = (1UL<<num_parent);
 	int i;
-	int lno = 0;
+	unsigned long lno = 0;
 
 	while (1) {
 		struct sline *sl = &sline[lno];
@@ -378,12 +548,15 @@ static void dump_sline(struct sline *sline, int cnt, int num_parent)
 			if (!(sline[hunk_end].flag & mark))
 				break;
 		for (i = 0; i <= num_parent; i++) putchar(combine_marker);
-		printf(" +%d,%d ", lno+1, hunk_end-lno);
+		for (i = 0; i < num_parent; i++)
+			show_parent_lno(sline, lno, hunk_end, cnt, i);
+		printf(" +%lu,%lu ", lno+1, hunk_end-lno);
 		for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 		putchar('\n');
 		while (lno < hunk_end) {
 			struct lline *ll;
 			int j;
+			unsigned long p_mask;
 			sl = &sline[lno++];
 			ll = sl->lost_head;
 			while (ll) {
@@ -393,33 +566,93 @@ static void dump_sline(struct sline *sline, int cnt, int num_parent)
 					else
 						putchar(' ');
 				}
-				putchar(' ');
 				puts(ll->line);
 				ll = ll->next;
 			}
+			p_mask = 1;
 			for (j = 0; j < num_parent; j++) {
-				if ((1UL<<j) & sl->flag)
-					putchar(' ');
-				else
+				if (p_mask & sl->flag)
 					putchar('+');
+				else
+					putchar(' ');
+				p_mask <<= 1;
 			}
-			printf(" %.*s\n", sl->len, sl->bol);
+			printf("%.*s\n", sl->len, sl->bol);
 		}
 	}
 }
 
-static void show_combined_diff(struct path_list *elem, int num_parent,
-			       int dense)
+static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
+			       int i, int j)
+{
+	/* We have already examined parent j and we know parent i
+	 * and parent j are the same, so reuse the combined result
+	 * of parent j for parent i.
+	 */
+	unsigned long lno, imask, jmask;
+	imask = (1UL<<i);
+	jmask = (1UL<<j);
+
+	for (lno = 0; lno < cnt; lno++) {
+		struct lline *ll = sline->lost_head;
+		sline->p_lno[i] = sline->p_lno[j];
+		while (ll) {
+			if (ll->parent_map & jmask)
+				ll->parent_map |= imask;
+			ll = ll->next;
+		}
+		if (sline->flag & jmask)
+			sline->flag |= imask;
+		sline++;
+	}
+}
+
+int show_combined_diff(struct combine_diff_path *elem, int num_parent,
+		       int dense, const char *header, int show_empty)
 {
 	unsigned long size, cnt, lno;
 	char *result, *cp, *ep;
 	struct sline *sline; /* survived lines */
-	int i;
-	char ourtmp[TMPPATHLEN];
+	int i, show_hunks, shown_header = 0;
+	char ourtmp_buf[TMPPATHLEN];
+	char *ourtmp = ourtmp_buf;
 
 	/* Read the result of merge first */
-	result = grab_blob(elem->sha1, &size);
-	write_to_temp_file(ourtmp, result, size);
+	if (memcmp(elem->sha1, null_sha1, 20)) {
+		result = grab_blob(elem->sha1, &size);
+		write_to_temp_file(ourtmp, result, size);
+	}
+	else {
+		struct stat st;
+		int fd;
+		ourtmp = elem->path;
+		if (0 <= (fd = open(ourtmp, O_RDONLY)) &&
+		    !fstat(fd, &st)) {
+			int len = st.st_size;
+			int cnt = 0;
+
+			size = len;
+			result = xmalloc(len + 1);
+			while (cnt < len) {
+				int done = xread(fd, result+cnt, len-cnt);
+				if (done == 0)
+					break;
+				if (done < 0)
+					die("read error '%s'", ourtmp);
+				cnt += done;
+			}
+			result[len] = 0;
+		}
+		else {
+			/* deleted file */
+			size = 0;
+			result = xmalloc(1);
+			result[0] = 0;
+			ourtmp = "/dev/null";
+		}
+		if (0 <= fd)
+			close(fd);
+	}
 
 	for (cnt = 0, cp = result; cp - result < size; cp++) {
 		if (*cp == '\n')
@@ -428,30 +661,69 @@ static void show_combined_diff(struct path_list *elem, int num_parent,
 	if (result[size-1] != '\n')
 		cnt++; /* incomplete line */
 
-	sline = xcalloc(cnt, sizeof(*sline));
+	sline = xcalloc(cnt+1, sizeof(*sline));
 	ep = result;
 	sline[0].bol = result;
 	for (lno = 0, cp = result; cp - result < size; cp++) {
 		if (*cp == '\n') {
+			sline[lno].lost_tail = &sline[lno].lost_head;
 			sline[lno].len = cp - sline[lno].bol;
-			sline[lno].flag = (1UL<<num_parent) - 1;
+			sline[lno].flag = 0;
 			lno++;
 			if (lno < cnt)
 				sline[lno].bol = cp + 1;
 		}
 	}
 	if (result[size-1] != '\n') {
+		sline[cnt-1].lost_tail = &sline[cnt-1].lost_head;
 		sline[cnt-1].len = size - (sline[cnt-1].bol - result);
-		sline[cnt-1].flag = (1UL<<num_parent) - 1;
+		sline[cnt-1].flag = 0;
 	}
 
-	for (i = 0; i < num_parent; i++)
-		combine_diff(elem->parent_sha1[i], ourtmp, sline, cnt, i);
+	sline[0].p_lno = xcalloc((cnt+1) * num_parent, sizeof(unsigned long));
+	for (lno = 0; lno < cnt; lno++)
+		sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
+
+	for (i = 0; i < num_parent; i++) {
+		int j;
+		for (j = 0; j < i; j++) {
+			if (!memcmp(elem->parent_sha1[i],
+				    elem->parent_sha1[j], 20)) {
+				reuse_combine_diff(sline, cnt, i, j);
+				break;
+			}
+		}
+		if (i <= j)
+			combine_diff(elem->parent_sha1[i], ourtmp, sline,
+				     cnt, i, num_parent);
+	}
 
-	make_hunks(sline, cnt, num_parent, dense);
+	show_hunks = make_hunks(sline, cnt, num_parent, dense);
 
-	dump_sline(sline, cnt, num_parent);
-	unlink(ourtmp);
+	if (show_hunks) {
+		if (header) {
+			shown_header++;
+			puts(header);
+		}
+		printf("diff --%s ", dense ? "cc" : "combined");
+		if (quote_c_style(elem->path, NULL, NULL, 0))
+			quote_c_style(elem->path, NULL, stdout, 0);
+		else
+			printf("%s", elem->path);
+		putchar('\n');
+		printf("index ");
+		for (i = 0; i < num_parent; i++) {
+			printf("%s%s",
+			       i ? "," : "",
+			       find_unique_abbrev(elem->parent_sha1[i],
+						  DEFAULT_ABBREV));
+		}
+		printf("..%s\n",
+		       find_unique_abbrev(elem->sha1, DEFAULT_ABBREV));
+		dump_sline(sline, cnt, num_parent);
+	}
+	if (ourtmp == ourtmp_buf)
+		unlink(ourtmp);
 	free(result);
 
 	for (i = 0; i < cnt; i++) {
@@ -464,7 +736,9 @@ static void show_combined_diff(struct path_list *elem, int num_parent,
 			}
 		}
 	}
+	free(sline[0].p_lno);
 	free(sline);
+	return shown_header;
 }
 
 int diff_tree_combined_merge(const unsigned char *sha1,
@@ -474,7 +748,7 @@ int diff_tree_combined_merge(const unsigned char *sha1,
 	struct commit *commit = lookup_commit(sha1);
 	struct diff_options diffopts;
 	struct commit_list *parents;
-	struct path_list *p, *paths = NULL;
+	struct combine_diff_path *p, *paths = NULL;
 	int num_parent, i, num_paths;
 
 	diff_setup(&diffopts);
@@ -504,23 +778,18 @@ int diff_tree_combined_merge(const unsigned char *sha1,
 			num_paths++;
 	}
 	if (num_paths || show_empty_merge) {
-		puts(header);
 		for (p = paths; p; p = p->next) {
 			if (!p->len)
 				continue;
-			printf("diff --combined ");
-			if (quote_c_style(p->path, NULL, NULL, 0))
-				quote_c_style(p->path, NULL, stdout, 0);
-			else
-				printf("%s", p->path);
-			putchar('\n');
-			show_combined_diff(p, num_parent, dense);
+			if (show_combined_diff(p, num_parent, dense, header,
+					       show_empty_merge))
+				header = NULL;
 		}
 	}
 
 	/* Clean things up */
 	while (paths) {
-		struct path_list *tmp = paths;
+		struct combine_diff_path *tmp = paths;
 		paths = paths->next;
 		free(tmp);
 	}