From 82f0d19b101271889b0b2ebe8cdb2f5eb4f64e6c Mon Sep 17 00:00:00 2001
From: Ron Yorston <rmy@pobox.com>
Date: Fri, 27 Jan 2023 13:11:35 +0000
Subject: diff: implement --binary flag

On Windows GNU diff uses text mode for input and output.  It also
has the '--binary' flag to use binary mode instead.  On Unix binary
mode is the default and the flag does nothing.

Alter diff to use text mode by default for input (though not output,
let's not go overboard).  Add the '--binary' flag to override this.

Costs 96-160 bytes.
---
 editors/diff.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/editors/diff.c b/editors/diff.c
index 17d41af8d..d91ecea51 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -119,6 +119,9 @@
 //usage:     "\n	-t	Expand tabs to spaces in output"
 //usage:     "\n	-U	Output LINES lines of context"
 //usage:     "\n	-w	Ignore all whitespace"
+//usage:	IF_PLATFORM_MINGW32(IF_FEATURE_DIFF_LONG_OPTIONS(
+//usage:     "\n	--binary  Treat input as binary, not text"
+//usage:	))
 
 #include "libbb.h"
 #include "common_bufsiz.h"
@@ -154,6 +157,9 @@ enum {                  /* Commandline flags */
 	FLAG_p,         /* not implemented */
 	FLAG_B,
 	FLAG_E,         /* not implemented */
+#if ENABLE_PLATFORM_MINGW32
+	FLAG_binary,
+#endif
 };
 #define FLAG(x) (1 << FLAG_##x)
 
@@ -720,7 +726,12 @@ static int diffreg(char *file[2])
 		int fd = STDIN_FILENO;
 		if (!LONE_DASH(file[i])) {
 			if (!(option_mask32 & FLAG(N))) {
+#if ENABLE_PLATFORM_MINGW32
+				int flag = (option_mask32 & FLAG(binary)) ? 0 : _O_TEXT;
+				fd = open_or_warn(file[i], O_RDONLY | flag);
+#else
 				fd = open_or_warn(file[i], O_RDONLY);
+#endif
 				if (fd == -1)
 					goto out;
 			} else {
@@ -751,10 +762,21 @@ static int diffreg(char *file[2])
 				xfunc_die();
 			if (fd != STDIN_FILENO)
 				close(fd);
+#if ENABLE_PLATFORM_MINGW32
+			if (!(option_mask32 & FLAG(binary))) {
+				/* Close and reopen tmpfile to get text mode */
+				close(fd_tmp);
+				fd_tmp = xopen(tmpfile[i], O_RDONLY | _O_TEXT);
+			}
+#endif
 			fd = fd_tmp;
 			xlseek(fd, 0, SEEK_SET);
 		}
+#if ENABLE_PLATFORM_MINGW32
+		fp[i] = fdopen(fd, (option_mask32 & FLAG(binary)) ? "r" : "rt");
+#else
 		fp[i] = fdopen(fd, "r");
+#endif
 	}
 
 	setup_common_bufsiz();
@@ -985,6 +1007,9 @@ static const char diff_longopts[] ALIGN1 =
 	"report-identical-files\0"   No_argument       "s"
 	"starting-file\0"            Required_argument "S"
 	"minimal\0"                  No_argument       "d"
+#if ENABLE_PLATFORM_MINGW32
+	"binary\0"                   No_argument       "\xff"
+#endif
 	;
 # define GETOPT32 getopt32long
 # define LONGOPTS ,diff_longopts
-- 
cgit v1.2.3-55-g6feb