diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_INCOMPLETE

The context marker use the exact same output pattern, so reuse it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diff.c b/diff.c
index 85bfd93..b2b2a19 100644
--- a/diff.c
+++ b/diff.c
@@ -564,6 +564,7 @@ enum diff_symbol {
 	DIFF_SYMBOL_WORDS_PORCELAIN,
 	DIFF_SYMBOL_WORDS,
 	DIFF_SYMBOL_CONTEXT,
+	DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 	DIFF_SYMBOL_PLUS,
 	DIFF_SYMBOL_MINUS,
 	DIFF_SYMBOL_NO_LF_EOF,
@@ -622,6 +623,7 @@ static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 	case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 		emit_line(o, "", "", line, len);
 		break;
+	case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 	case DIFF_SYMBOL_CONTEXT_MARKER:
 		context = diff_get_color_opt(o, DIFF_CONTEXT);
 		reset = diff_get_color_opt(o, DIFF_RESET);
@@ -1448,8 +1450,8 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 	default:
 		/* incomplete line at the end */
 		ecbdata->lno_in_preimage++;
-		emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
-			  reset, line, len);
+		emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
+				 line, len, 0);
 		break;
 	}
 }