Subject: [PATCHv2 11/20] diff.c: convert emit_rewrite_lines to use emit_line_*

From: Stefan Beller <[email-masked]>
Date: Tue, 16 May 2017 19:58:48 -0700

In a later patch, I want to propose an option to detect&color
moved lines in a diff, which cannot be done in a one-pass over
the diff. Instead we need to go over the whole diff twice,
because we cannot detect the first line of the two corresponding
lines (+ and -) that got moved.

So to prepare the diff machinery for two pass algorithms
(i.e. buffer it all up and then operate on the result),
move all emissions to places, such that the only emitting
function is emit_line_0.

This covers emit_rewrite_lines.

Signed-off-by: Stefan Beller <[email-masked]>
---
 diff.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/diff.c b/diff.c
index 3dda9f3c8e..690794aeb8 100644
--- a/diff.c
+++ b/diff.c
@@ -722,15 +722,25 @@ static void add_line_count(struct strbuf *out, int count)
 static void emit_rewrite_lines(struct emit_callback *ecb,
 			       int prefix, const char *data, int size)
 {
-	const char *endp = NULL;
-	static const char *nneof = " No newline at end of file\n";
 	const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
+	struct strbuf sb = STRBUF_INIT;
 
 	while (0 < size) {
 		int len;
 
-		endp = memchr(data, '\n', size);
-		len = endp ? (endp - data + 1) : size;
+		const char *endp = memchr(data, '\n', size);
+		if (endp)
+			len = endp - data + 1;
+		else {
+			while (0 < size) {
+				strbuf_addch(&sb, *data);
+				size -= len;
+				data += len;
+			}
+			strbuf_addch(&sb, '\n');
+			data = sb.buf;
+			len = sb.len;
+		}
 		if (prefix != '+') {
 			ecb->lno_in_preimage++;
 			emit_del_line(reset, ecb, data, len);
@@ -741,12 +751,13 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 		size -= len;
 		data += len;
 	}
-	if (!endp) {
+	if (sb.len) {
+		static const char *nneof = "\\ No newline at end of file\n";
 		const char *context = diff_get_color(ecb->color_diff,
 						     DIFF_CONTEXT);
-		putc('\n', ecb->opt->file);
-		emit_line(ecb->opt, context, reset, 1, '\\',
-			  nneof, strlen(nneof));
+		emit_line(ecb->opt, context, reset, 1, 0,
+			    nneof, strlen(nneof));
+		strbuf_release(&sb);
 	}
 }
 
-- 
2.13.0.18.g7d86cc8ba0