Add (r)evert prompt to "File changed on disk; really edit the buffer"

prompt.

input, ok lum@, man bit ok jmc@, ok benno@

4 files changed, 83 insertions, 28 deletions

diff --git a/usr.bin/mg/buffer.c b/usr.bin/mg/buffer.c
index 5f3330c3ee1..c81c50dfce8 100644
--- a/usr.bin/mg/buffer.c
+++ b/usr.bin/mg/buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buffer.c,v 1.83 2012/10/22 08:22:04 florian Exp $	*/
+/*	$OpenBSD: buffer.c,v 1.84 2012/10/22 08:31:42 florian Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -856,11 +856,18 @@ checkdirty(struct buffer *bp)
 			bp->b_flag |= BFDIRTY;
 
 	if ((bp->b_flag & (BFDIRTY | BFIGNDIRTY)) == BFDIRTY) {
-		if ((s = eyorn("File changed on disk; really edit the buffer"))
-		    != TRUE)
+		s = eynorr("File changed on disk; really edit the buffer");
+		switch (s) {
+		case TRUE:
+			bp->b_flag &= ~BFDIRTY;
+			bp->b_flag |= BFIGNDIRTY;
+			return (TRUE);
+		case REVERT:
+			dorevert();
+			return (FALSE);
+		default:
 			return (s);
-		bp->b_flag &= ~BFDIRTY;
-		bp->b_flag |= BFIGNDIRTY;
+		}
 	}
 
 	return (TRUE);
@@ -873,10 +880,8 @@ checkdirty(struct buffer *bp)
 int
 revertbuffer(int f, int n)
 {
-	struct mgwin *wp = wheadp;
-	struct buffer *bp = wp->w_bufp;
+	struct buffer *bp = wheadp->w_bufp;
 	char fbuf[NFILEN + 32];
-	int lineno;
 
 	if (bp->b_fname[0] == 0) {
 		ewprintf("Cannot revert buffer not associated with any files.");
@@ -885,26 +890,36 @@ revertbuffer(int f, int n)
 
 	snprintf(fbuf, sizeof(fbuf), "Revert buffer from file %s", bp->b_fname);
 
-	if (eyorn(fbuf)) {
-		if (access(bp->b_fname, F_OK|R_OK) != 0) {
-			if (errno == ENOENT)
-				ewprintf("File %s no longer exists!",
-				    bp->b_fname);
-			else
-				ewprintf("File %s is no longer readable!",
-				    bp->b_fname);
-			return (FALSE);
-		}
+	if (eyorn(fbuf))
+		return dorevert();
 
-		/* Save our current line, so we can go back after reloading. */
-		lineno = wp->w_dotline;
+	return (FALSE);
+}
 
-		/* Prevent readin from asking if we want to kill the buffer. */
-		curbp->b_flag &= ~BFCHG;
+int
+dorevert()
+{
+	struct mgwin *wp = wheadp;
+	struct buffer *bp = wp->w_bufp;
+	int lineno;
 
-		if (readin(bp->b_fname))
-			return(setlineno(lineno));
+	if (access(bp->b_fname, F_OK|R_OK) != 0) {
+		if (errno == ENOENT)
+			ewprintf("File %s no longer exists!",
+			    bp->b_fname);
+		else
+			ewprintf("File %s is no longer readable!",
+			    bp->b_fname);
+		return (FALSE);
 	}
 
+	/* Save our current line, so we can go back after reloading. */
+	lineno = wp->w_dotline;
+
+	/* Prevent readin from asking if we want to kill the buffer. */
+	curbp->b_flag &= ~BFCHG;
+
+	if (readin(bp->b_fname))
+		return(setlineno(lineno));
 	return (FALSE);
 }
diff --git a/usr.bin/mg/def.h b/usr.bin/mg/def.h
index c24c8505a73..2efe5cc6f36 100644
--- a/usr.bin/mg/def.h
+++ b/usr.bin/mg/def.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: def.h,v 1.126 2012/10/12 21:13:46 jasper Exp $	*/
+/*	$OpenBSD: def.h,v 1.127 2012/10/22 08:31:42 florian Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -37,6 +37,7 @@ typedef int	(*PF)(int, int);	/* generally useful type */
 #define TRUE	1		/* True, yes, good, etc.	 */
 #define ABORT	2		/* Death, ^G, abort, etc.	 */
 #define UERROR	3		/* User Error.			 */
+#define REVERT	4		/* Revert the buffer		 */
 
 #define KCLEAR	2		/* clear echo area		 */
 
@@ -415,6 +416,7 @@ int		 popbuftop(struct buffer *, int);
 int		 getbufcwd(char *, size_t);
 int		 checkdirty(struct buffer *);
 int		 revertbuffer(int, int);
+int		 dorevert();
 
 /* display.c */
 int		vtresize(int, int, int);
@@ -426,6 +428,7 @@ int		linenotoggle(int, int);
 /* echo.c X */
 void		 eerase(void);
 int		 eyorn(const char *);
+int		 eynorr(const char *);
 int		 eyesno(const char *);
 void		 ewprintf(const char *fmt, ...);
 char		*ereply(const char *, char *, size_t, ...);
diff --git a/usr.bin/mg/echo.c b/usr.bin/mg/echo.c
index beff2f1420b..1e500b99ec2 100644
--- a/usr.bin/mg/echo.c
+++ b/usr.bin/mg/echo.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: echo.c,v 1.51 2012/09/25 19:16:52 lum Exp $	*/
+/*	$OpenBSD: echo.c,v 1.52 2012/10/22 08:31:42 florian Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -72,6 +72,36 @@ eyorn(const char *sp)
 }
 
 /*
+ * Ask a "yes", "no" or "revert" question.  Return ABORT if the user answers
+ * the question with the abort ("^G") character.  Return FALSE for "no",
+ * TRUE for "yes" and REVERT for "revert". No formatting services are
+ * available.  No newline required.
+ */
+int
+eynorr(const char *sp)
+{
+	int	 s;
+
+	if (inmacro)
+		return (TRUE);
+
+	ewprintf("%s? (y, n or r) ", sp);
+	for (;;) {
+		s = getkey(FALSE);
+		if (s == 'y' || s == 'Y' || s == ' ')
+			return (TRUE);
+		if (s == 'n' || s == 'N' || s == CCHR('M'))
+			return (FALSE);
+		if (s == 'r' || s == 'R')
+			return (REVERT);
+		if (s == CCHR('G'))
+			return (ctrlg(FFRAND, 1));
+		ewprintf("Please answer y, n or r.");
+	}
+	/* NOTREACHED */
+}
+
+/*
  * Like eyorn, but for more important questions.  User must type all of
  * "yes" or "no" and the trailing newline.
  */
diff --git a/usr.bin/mg/mg.1 b/usr.bin/mg/mg.1
index baab1863ce1..e47474365ee 100644
--- a/usr.bin/mg/mg.1
+++ b/usr.bin/mg/mg.1
@@ -1,7 +1,7 @@
-.\"	$OpenBSD: mg.1,v 1.69 2012/10/12 21:13:47 jasper Exp $
+.\"	$OpenBSD: mg.1,v 1.70 2012/10/22 08:31:42 florian Exp $
 .\" This file is in the public domain.
 .\"
-.Dd $Mdocdate: October 12 2012 $
+.Dd $Mdocdate: October 22 2012 $
 .Dt MG 1
 .Os
 .Sh NAME
@@ -51,6 +51,13 @@ At present, windows may only be split horizontally, so each window is
 delineated by a modeline at the bottom.
 If changes are made to a buffer, it will be reflected in all open windows.
 .Pp
+If a file is changed outside
+.Nm
+and its buffer is about to be changed,
+.Nm
+prompts if the change should go ahead (y), not go ahead (n) or if the buffer
+should be reverted (r) to the latest file on disk.
+.Pp
 If a buffer name begins and ends with an asterisk, the buffer is considered
 throwaway; i.e. the user will not be prompted to save changes when
 the buffer is killed.