[PATCH v3 3/4] diff.c: add emit_del_line() and emit_context_line()

From: Junio C Hamano <gitster@pobox.com>
Date: May 27, 2015, 06:30 UTC
Message-ID: <1432708232-29892-4-git-send-email-gitster@pobox.com>
In-Reply-To: <1432708232-29892-1-git-send-email-gitster@pobox.com>

Traditionally, we only had emit_add_line() helper, which knows how to find and paint whitespace breakages on the given line, because we only care about whitespace breakages introduced in new lines. The context lines and old (i.e. deleted) lines are emitted with a simpler emit_line_0() that paints the entire line in plain or old colors.

Identify callers of emit_line_0() that show deleted lines and context lines, have them call new helpers, emit_del_line() and emit_context_line(), so that we can later tweak what is done to these two classes of lines.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 diff.c | 50 ++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/diff.c b/diff.c
index d1bd534..c575c45 100644
--- a/diff.c
+++ b/diff.c
@@ -498,6 +498,24 @@ static void emit_add_line(const char *reset,
 	}
 }
 
+static void emit_del_line(const char *reset,
+			  struct emit_callback *ecbdata,
+			  const char *line, int len)
+{
+	const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_OLD);
+
+	emit_line_0(ecbdata->opt, set, reset, '-', line, len);
+}
+
+static void emit_context_line(const char *reset,
+			      struct emit_callback *ecbdata,
+			      const char *line, int len)
+{
+	const char *set = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
+
+	emit_line_0(ecbdata->opt, set, reset, ' ', line, len);
+}
+
 static void emit_hunk_header(struct emit_callback *ecbdata,
 			     const char *line, int len)
 {
@@ -603,7 +621,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 {
 	const char *endp = NULL;
 	static const char *nneof = " No newline at end of file\n";
-	const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 	const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
 	while (0 < size) {
@@ -613,8 +630,7 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 		len = endp ? (endp - data + 1) : size;
 		if (prefix != '+') {
 			ecb->lno_in_preimage++;
-			emit_line_0(ecb->opt, old, reset, '-',
-				    data, len);
+			emit_del_line(reset, ecb, data, len);
 		} else {
 			ecb->lno_in_postimage++;
 			emit_add_line(reset, ecb, data, len);
@@ -1250,17 +1266,27 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 		return;
 	}
 
-	if (line[0] != '+') {
-		const char *color =
-			diff_get_color(ecbdata->color_diff,
-				       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
-		ecbdata->lno_in_preimage++;
-		if (line[0] == ' ')
-			ecbdata->lno_in_postimage++;
-		emit_line(ecbdata->opt, color, reset, line, len);
-	} else {
+	switch (line[0]) {
+	case '+':
 		ecbdata->lno_in_postimage++;
 		emit_add_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	case '-':
+		ecbdata->lno_in_preimage++;
+		emit_del_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	case ' ':
+		ecbdata->lno_in_postimage++;
+		ecbdata->lno_in_preimage++;
+		emit_context_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	default:
+		/* incomplete line at the end */
+		ecbdata->lno_in_preimage++;
+		emit_line(ecbdata->opt,
+			  diff_get_color(ecbdata->color_diff, DIFF_PLAIN),
+			  reset, line, len);
+		break;
 	}
 }

-- 
2.4.2-503-g3e4528a