Add 'U' command to E(ditor). It reverts label to state it was in

when entering E(ditor) mode. Clean up 'u' code and make more effort
to keep label and mountpoint info in sync. Makes 'u' undo-able so
those with vi fingers can apply and revert changes (with perhaps a
'p' or two in between) to validate changes.

'U' suggested by deraadt@.

ok deraadt@

1 files changed, 64 insertions, 71 deletions

diff --git a/sbin/disklabel/editor.c b/sbin/disklabel/editor.c
index 74a9d7a588c..eb2a37ec8c4 100644
--- a/sbin/disklabel/editor.c
+++ b/sbin/disklabel/editor.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: editor.c,v 1.178 2009/03/28 07:08:32 otto Exp $	*/
+/*	$OpenBSD: editor.c,v 1.179 2009/03/28 16:18:50 krw Exp $	*/
 
 /*
  * Copyright (c) 1997-2000 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -17,7 +17,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$OpenBSD: editor.c,v 1.178 2009/03/28 07:08:32 otto Exp $";
+static char rcsid[] = "$OpenBSD: editor.c,v 1.179 2009/03/28 16:18:50 krw Exp $";
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -109,7 +109,7 @@ void	getdisktype(struct disklabel *, char *, char *);
 void	find_bounds(struct disklabel *);
 void	set_bounds(struct disklabel *);
 struct diskchunk *free_chunks(struct disklabel *);
-char **	mpcopy(char **, char **);
+void	mpcopy(char **, char **);
 int	micmp(const void *, const void *);
 int	mpequal(char **, char **);
 int	mpsave(struct disklabel *, char **, char *, char *);
@@ -136,17 +136,19 @@ static int expert;
 int
 editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 {
-	struct disklabel lastlabel, tmplabel, label = *lp;
+	struct disklabel origlabel, lastlabel, tmplabel, label = *lp;
 	struct disklabel *disk_geop;
 	struct partition *pp;
 	FILE *fp;
 	char buf[BUFSIZ], *cmd, *arg;
-	char **mountpoints = NULL, **omountpoints = NULL, **tmpmountpoints = NULL;
+	char **mountpoints = NULL, **omountpoints = NULL;
+	char **origmountpoints = NULL, **tmpmountpoints = NULL;
 
 	/* Alloc and init mount point info */
 	if (fstabfile) {
 		if (!(mountpoints = calloc(MAXPARTITIONS, sizeof(char *))) ||
 		    !(omountpoints = calloc(MAXPARTITIONS, sizeof(char *))) ||
+		    !(origmountpoints = calloc(MAXPARTITIONS, sizeof(char *))) ||
 		    !(tmpmountpoints = calloc(MAXPARTITIONS, sizeof(char *))))
 			errx(4, "out of memory");
 	}
@@ -195,6 +197,9 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 	if (label.d_interleave == 0)
 		label.d_interleave = 1;
 
+	/* Save the (U)ndo label, origmountpoints is already NULLs. */
+	origlabel = label;
+
 	if (aflag)
 		editor_allocspace(&label, mountpoints, 0);
 
@@ -211,101 +216,61 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 			continue;
 		arg = strtok(NULL, " \t\r\n");
 
-		switch (*cmd) {
+		if ((*cmd != 'u') && (*cmd != 'U')) {
+			/*
+			 * Save undo info in case the command tries to make
+			 * changes but decides not to.
+			 */
+			tmplabel = lastlabel;
+			lastlabel = label;
+			if (mountpoints != NULL) {
+				mpcopy(tmpmountpoints, omountpoints);
+				mpcopy(omountpoints, mountpoints);
+			}
+		}
 
+		switch (*cmd) {
 		case '?':
 		case 'h':
 			editor_help(arg ? arg : "");
 			break;
 
 		case 'A':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			editor_allocspace(&label, mountpoints, 1);
 			break;
 		case 'a':
-			tmplabel = lastlabel;
-			lastlabel = label;
-			if (mountpoints != NULL) {
-				mpcopy(tmpmountpoints, omountpoints);
-				mpcopy(omountpoints, mountpoints);
-			}
 			editor_add(&label, mountpoints, arg);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
-			if (mountpoints != NULL && mpequal(omountpoints, tmpmountpoints))
-				mpcopy(omountpoints, tmpmountpoints);
 			break;
 
 		case 'b':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			set_bounds(&label);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
 			break;
 
 		case 'c':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			editor_change(&label, arg);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
 			break;
 
 		case 'D':
-			tmplabel = lastlabel;
-			lastlabel = label;
-			if (ioctl(f, DIOCGPDINFO, &label) == 0) {
+			if (ioctl(f, DIOCGPDINFO, &label) == 0)
 				dflag = 1;
-			} else {
+			else
 				warn("unable to get default partition table");
-				lastlabel = tmplabel;
-			}
 			break;
 
 		case 'd':
-			tmplabel = lastlabel;
-			lastlabel = label;
-			if (mountpoints != NULL) {
-				mpcopy(tmpmountpoints, omountpoints);
-				mpcopy(omountpoints, mountpoints);
-			}
 			editor_delete(&label, mountpoints, arg);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
-			if (mountpoints != NULL && mpequal(omountpoints, tmpmountpoints))
-				mpcopy(omountpoints, tmpmountpoints);
 			break;
 
 		case 'e':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			edit_parms(&label);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
 			break;
 
 		case 'g':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			set_geometry(&label, disk_geop, lp, arg);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
 			break;
 
 		case 'm':
-			tmplabel = lastlabel;
-			lastlabel = label;
-			if (mountpoints != NULL) {
-				mpcopy(tmpmountpoints, omountpoints);
-				mpcopy(omountpoints, mountpoints);
-			}
 			editor_modify(&label, mountpoints, arg);
-			if (memcmp(&label, &lastlabel, sizeof(label)) == 0)
-				lastlabel = tmplabel;
-			if (mountpoints != NULL && mpequal(omountpoints, tmpmountpoints))
-				mpcopy(omountpoints, tmpmountpoints);
 			break;
 
 		case 'n':
@@ -314,11 +279,7 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 				    "without the -f flag.\n", stderr);
 				break;
 			}
-			mpcopy(tmpmountpoints, omountpoints);
-			mpcopy(omountpoints, mountpoints);
 			editor_name(&label, mountpoints, arg);
-			if (mpequal(omountpoints, tmpmountpoints))
-				mpcopy(omountpoints, tmpmountpoints);
 			break;
 
 		case 'p':
@@ -416,18 +377,40 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 			}
 			break;
 
+		case 'U':
+			if (memcmp(&label, &origlabel, sizeof(label)) == 0 &&
+			    (mountpoints == NULL || 
+			    mpequal(mountpoints, origmountpoints))) {
+				puts("Nothing to undo!");
+			} else {
+				tmplabel = label;
+				label = origlabel;
+				lastlabel = tmplabel;
+				/* Restore mountpoints */
+				if (mountpoints != NULL) {
+					mpcopy(tmpmountpoints, mountpoints);
+					mpcopy(mountpoints, origmountpoints);
+					mpcopy(omountpoints, tmpmountpoints);
+				}
+				puts("All changes undone.");
+			}
+			break;
+
 		case 'u':
 			if (memcmp(&label, &lastlabel, sizeof(label)) == 0 &&
-			    mountpoints != NULL &&
-			    mpequal(mountpoints, omountpoints)) {
+			    (mountpoints == NULL ||
+			    mpequal(mountpoints, omountpoints))) {
 				puts("Nothing to undo!");
 			} else {
 				tmplabel = label;
 				label = lastlabel;
 				lastlabel = tmplabel;
 				/* Restore mountpoints */
-				if (mountpoints != NULL)
+				if (mountpoints != NULL) {
+					mpcopy(tmpmountpoints, mountpoints);
 					mpcopy(mountpoints, omountpoints);
+					mpcopy(omountpoints, tmpmountpoints);
+				}
 				puts("Last change undone.");
 			}
 			break;
@@ -460,9 +443,9 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 			break;
 
 		case 'z':
-			tmplabel = lastlabel;
-			lastlabel = label;
 			zero_partitions(&label);
+			if (mountpoints != NULL)
+				mpcopy(mountpoints, origmountpoints);
 			break;
 
 		case '\n':
@@ -472,6 +455,17 @@ editor(struct disklabel *lp, int f, char *dev, char *fstabfile, int aflag)
 			printf("Unknown option: %c ('?' for help)\n", *cmd);
 			break;
 		}
+
+		/*
+		 * If no changes were made to label or mountpoints, then
+		 * restore undo info.
+		 */
+		if (memcmp(&label, &lastlabel, sizeof(label)) == 0 &&
+		    (mountpoints == NULL || 
+		    mpequal(mountpoints, omountpoints))) {
+			lastlabel = tmplabel;
+			mpcopy(omountpoints, tmpmountpoints);
+		}
 	}
 }
 
@@ -1738,7 +1732,7 @@ editor_help(char *arg)
 	}
 }
 
-char **
+void
 mpcopy(char **to, char **from)
 {
 	int i;
@@ -1758,7 +1752,6 @@ mpcopy(char **to, char **from)
 			to[i] = NULL;
 		}
 	}
-	return(to);
 }
 
 int