diff.c: emit_diff_symbol learns about DIFF_SYMBOL_BINARY_FILES

we could save a little bit of memory when buffering in a later mode
by just passing the inner part ("%s and %s", file1, file 2), but
those a just a few bytes, so instead let's reuse the implementation from
DIFF_SYMBOL_HEADER and keep the whole line around.

Signed-off-by: Stefan Beller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: stefanbeller

diff.c

@@ -561,6 +561,7 @@ static void emit_line(struct diff_options *o, const char *set, const char *reset
 }
 
 enum diff_symbol {
+	DIFF_SYMBOL_BINARY_FILES,
 	DIFF_SYMBOL_HEADER,
 	DIFF_SYMBOL_FILEPAIR_PLUS,
 	DIFF_SYMBOL_FILEPAIR_MINUS,
@@ -690,6 +691,7 @@ static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			line, reset,
 			strchr(line, ' ') ? "\t" : "");
 		break;
+	case DIFF_SYMBOL_BINARY_FILES:
 	case DIFF_SYMBOL_HEADER:
 		fprintf(o->file, "%s", line);
 		break;
@@ -2542,6 +2544,7 @@ static void builtin_diff(const char *name_a,
 	} else if (!DIFF_OPT_TST(o, TEXT) &&
 	    ( (!textconv_one && diff_filespec_is_binary(one)) ||
 	      (!textconv_two && diff_filespec_is_binary(two)) )) {
+		struct strbuf sb = STRBUF_INIT;
 		if (!one->data && !two->data &&
 		    S_ISREG(one->mode) && S_ISREG(two->mode) &&
 		    !DIFF_OPT_TST(o, BINARY)) {
@@ -2554,8 +2557,11 @@ static void builtin_diff(const char *name_a,
 			}
 			emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
 					 header.buf, header.len, 0);
-			fprintf(o->file, "%sBinary files %s and %s differ\n",
-				line_prefix, lbl[0], lbl[1]);
+			strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
+				    diff_line_prefix(o), lbl[0], lbl[1]);
+			emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
+					 sb.buf, sb.len, 0);
+			strbuf_release(&sb);
 			goto free_ab_and_return;
 		}
 		if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
@@ -2572,9 +2578,13 @@ static void builtin_diff(const char *name_a,
 		strbuf_reset(&header);
 		if (DIFF_OPT_TST(o, BINARY))
 			emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
-		else
-			fprintf(o->file, "%sBinary files %s and %s differ\n",
-				line_prefix, lbl[0], lbl[1]);
+		else {
+			strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
+				    diff_line_prefix(o), lbl[0], lbl[1]);
+			emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
+					 sb.buf, sb.len, 0);
+			strbuf_release(&sb);
+		}
 		o->found_changes = 1;
 	} else {
 		/* Crazy xdl interfaces.. */