diff(1) gnu -L compatibility

[YAMAMOTO Takashi <yamt_(_at_)_mwd_(_dot_)_biglobe_(_dot_)_ne_(_dot_)_jp>]

hi,

the attached patch is to make diff(1) more compatible with the gnu version.
namely, if -L is specified twice, use it for the second filename.
this feature seems to be used by subversion.

YAMAMOTO Takashi
Index: diff.1
===================================================================
RCS file: /cvs/src/usr.bin/diff/diff.1,v
retrieving revision 1.26
diff -u -p -r1.26 diff.1
--- diff.1	20 Jun 2004 18:47:45 -0000	1.26
+++ diff.1	8 Dec 2004 18:14:25 -0000
@@ -223,7 +223,8 @@ after all text file differences are repo
 .It Fl L Ar label
 Print
 .Ar label
-instead of the first file name and time in the context or unified diff header.
+instead of the first (and second, if this options is specified twice)
+file name and time in the context or unified diff header.
 .It Fl p
 With unified and context diffs, show with each change
 the first 40 characters of the last line before the context beginning
Index: diff.c
===================================================================
RCS file: /cvs/src/usr.bin/diff/diff.c,v
retrieving revision 1.47
diff -u -p -r1.47 diff.c
--- diff.c	7 Dec 2004 11:53:29 -0000	1.47
+++ diff.c	8 Dec 2004 18:14:25 -0000
@@ -43,7 +43,7 @@ static const char rcsid[] = "$OpenBSD: d
 int	 aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, pflag, rflag;
 int	 sflag, tflag, Tflag, wflag;
 int	 format, context, status;
-char	*start, *ifdefname, *diffargs, *label, *ignore_pats;
+char	*start, *ifdefname, *diffargs, *label1, *label2, *ignore_pats;
 struct stat stb1, stb2;
 struct excludes *excludes_list;
 regex_t	 ignore_re;
@@ -149,7 +149,12 @@ main(int argc, char **argv)
 			iflag = 1;
 			break;
 		case 'L':
-			label = optarg;
+			if (label1 == NULL)
+				label1 = optarg;
+			else if (label2 == NULL)
+				label2 = optarg;
+			else
+				usage();
 			break;
 		case 'l':
 			lflag = 1;
Index: diff.h
===================================================================
RCS file: /cvs/src/usr.bin/diff/diff.h,v
retrieving revision 1.28
diff -u -p -r1.28 diff.h
--- diff.h	20 Jun 2004 18:47:45 -0000	1.28
+++ diff.h	8 Dec 2004 18:14:25 -0000
@@ -76,7 +76,7 @@ struct excludes {
 extern int	aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, pflag, rflag,
 		sflag, tflag, Tflag, wflag;
 extern int	format, context, status;
-extern char	*start, *ifdefname, *diffargs, *label, *ignore_pats;
+extern char	*start, *ifdefname, *diffargs, *label1, *label2, *ignore_pats;
 extern struct	stat stb1, stb2;
 extern struct	excludes *excludes_list;
 extern regex_t	ignore_re;
Index: diffreg.c
===================================================================
RCS file: /cvs/src/usr.bin/diff/diffreg.c,v
retrieving revision 1.60
diff -u -p -r1.60 diffreg.c
--- diffreg.c	27 Nov 2004 19:16:25 -0000	1.60
+++ diffreg.c	8 Dec 2004 18:14:26 -0000
@@ -1048,16 +1048,22 @@ proceed:
 			/*
 			 * Print the context/unidiff header first time through.
 			 */
-			if (label != NULL)
+			if (label1 != NULL)
 				printf("%s %s\n",
-				    format == D_CONTEXT ? "***" : "---", label);
+				    format == D_CONTEXT ? "***" : "---",
+				    label1);
 			else
 				printf("%s %s\t%s",
 				    format == D_CONTEXT ? "***" : "---", file1,
 				    ctime(&stb1.st_mtime));
-			printf("%s %s\t%s",
-			    format == D_CONTEXT ? "---" : "+++", file2,
-			    ctime(&stb2.st_mtime));
+			if (label2 != NULL)
+				printf("%s %s\n",
+				    format == D_CONTEXT ? "---" : "+++",
+				    label2);
+			else
+				printf("%s %s\t%s",
+				    format == D_CONTEXT ? "---" : "+++", file2,
+				    ctime(&stb2.st_mtime));
 			anychange = 1;
 		} else if (a > context_vec_ptr->b + (2 * context) + 1 &&
 		    c > context_vec_ptr->d + (2 * context) + 1) {