Fix a bug where inserting a file resulted in an incorrect

line-number count for a buffer (M-X insert-file, M-> to reproduce).
While here, fix a number of bugs with incorrect line numbers
after swap point-and-mark

Originally reported via debian's bug tracking system. Fix tested by
Han Boetes and Deanna Phillips.

3 files changed, 49 insertions, 22 deletions

diff --git a/usr.bin/mg/file.c b/usr.bin/mg/file.c
index 8b245c57de2..70fb05ff448 100644
--- a/usr.bin/mg/file.c
+++ b/usr.bin/mg/file.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: file.c,v 1.63 2006/11/17 08:45:31 kjell Exp $	*/
+/*	$OpenBSD: file.c,v 1.64 2006/12/24 01:20:53 kjell Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -337,34 +337,32 @@ insertfile(char *fname, char *newname, int replacebuf)
 		(void)strlcat(bp->b_cwd, "/", sizeof(bp->b_cwd));
 	}
 	opos = curwp->w_doto;
-
-	/* Open a new line, at point, and start inserting after it. */
-	x2 = undo_enable(FALSE);
 	oline = curwp->w_dotline;
+	/*
+	 * Open a new line at dot and start inserting after it.
+	 * We will delete this newline after insertion.
+	 * Disable undo, as we create the undo record manually.
+	 */
+	x2 = undo_enable(FALSE);
 	(void)lnewline();
 	olp = lback(curwp->w_dotp);
-	if (olp == curbp->b_headp) {
-		/* if at end of buffer, create a line to insert before */
-		(void)lnewline();
-		curwp->w_dotp = lback(curwp->w_dotp);
-	}
 	undo_enable(x2);
 
-	/* don't count fake lines at the end */
 	nline = 0;
 	siz = 0;
 	while ((s = ffgetline(line, linesize, &nbytes)) != FIOERR) {
-doneread:
+retry:
 		siz += nbytes + 1;
 		switch (s) {
 		case FIOSUC:
 			/* FALLTHRU */
 		case FIOEOF:
-			/* the last line of the file */
 			++nline;
 			if ((lp1 = lalloc(nbytes)) == NULL) {
 				/* keep message on the display */
 				s = FIOERR;
+				undo_add_insert(olp, opos,
+				    siz - nbytes - 1 - 1);
 				goto endoffile;
 			}
 			bcopy(line, &ltext(lp1)[0], nbytes);
@@ -373,8 +371,10 @@ doneread:
 			lp1->l_fp = curwp->w_dotp;
 			lp1->l_bp = lp2;
 			curwp->w_dotp->l_bp = lp1;
-			if (s == FIOEOF)
+			if (s == FIOEOF) {
+				undo_add_insert(olp, opos, siz - 1);
 				goto endoffile;
+			}
 			break;
 		case FIOLONG: {
 				/* a line too long to fit in our buffer */
@@ -398,7 +398,7 @@ doneread:
 				linesize = newsize;
 				if (s == FIOERR)
 					goto endoffile;
-				goto doneread;
+				goto retry;
 			}
 		default:
 			ewprintf("Unknown code %d reading file", s);
@@ -407,8 +407,6 @@ doneread:
 		}
 	}
 endoffile:
-	undo_add_insert(olp, opos, siz - 1);
-
 	/* ignore errors */
 	ffclose(NULL);
 	/* don't zap an error */
@@ -421,7 +419,17 @@ endoffile:
 	/* set mark at the end of the text */
 	curwp->w_dotp = curwp->w_markp = lback(curwp->w_dotp);
 	curwp->w_marko = llength(curwp->w_markp);
-	(void)ldelnewline();
+	curwp->w_markline = oline + nline + 1;
+	/*
+	 * if we are at the end of the file, ldelnewline is a no-op,
+	 * but we still need to decrement the line and markline counts
+	 * as we've accounted for this fencepost in our arithmetic
+	 */
+	if (lforw(curwp->w_dotp) == curwp->w_bufp->b_headp) {
+		curwp->w_bufp->b_lines--;
+		curwp->w_markline--;
+	} else
+		(void)ldelnewline();
 	curwp->w_dotp = olp;
 	curwp->w_doto = opos;
 	curwp->w_dotline = oline;
diff --git a/usr.bin/mg/fileio.c b/usr.bin/mg/fileio.c
index 82e8d978fc5..9a148063ffa 100644
--- a/usr.bin/mg/fileio.c
+++ b/usr.bin/mg/fileio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fileio.c,v 1.79 2006/11/19 16:51:19 deraadt Exp $	*/
+/*	$OpenBSD: fileio.c,v 1.80 2006/12/24 01:20:53 kjell Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -139,6 +139,7 @@ ffputbuf(struct buffer *bp)
  * in the supplied buffer. Stop on end of file or end of
  * line.  When FIOEOF is returned, there is a valid line
  * of data without the normally implied \n.
+ * If the line length exceeds nbuf, FIOLONG is returned.
  */
 int
 ffgetline(char *buf, int nbuf, int *nbytes)
diff --git a/usr.bin/mg/line.c b/usr.bin/mg/line.c
index 47b341c0cc2..ac600887381 100644
--- a/usr.bin/mg/line.c
+++ b/usr.bin/mg/line.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: line.c,v 1.43 2006/11/17 08:45:31 kjell Exp $	*/
+/*	$OpenBSD: line.c,v 1.44 2006/12/24 01:20:53 kjell Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -309,6 +309,13 @@ linsert(int n, int c)
 	return (TRUE);
 }
 
+/*
+ * Do the work of inserting a newline at the given line/offset.
+ * If mark is on the current line, we may have to move the markline
+ * to keep line numbers in sync.
+ * lnewline_at assumes the current buffer is writable. Checking for
+ * this fact should be done by the caller.
+ */
 int
 lnewline_at(struct line *lp1, int doto)
 {
@@ -318,6 +325,14 @@ lnewline_at(struct line *lp1, int doto)
 
 	lchange(WFFULL);
 
+	curwp->w_bufp->b_lines++;
+	/* Check if mark is past dot (even on current line) */
+	if (curwp->w_markline > curwp->w_dotline  ||
+	   (curwp->w_dotline == curwp->w_markline &&
+	    curwp->w_marko >= doto))
+		curwp->w_markline++;
+	curwp->w_dotline++;
+
 	/* If start of line, allocate a new line instead of copying */
 	if (doto == 0) {
 		/* new first part */
@@ -377,8 +392,6 @@ lnewline(void)
 		ewprintf("Buffer is read only");
 		return (FALSE);
 	}
-	curwp->w_bufp->b_lines++;
-	curwp->w_dotline++;
 	return (lnewline_at(curwp->w_dotp, curwp->w_doto));
 }
 
@@ -472,7 +485,9 @@ ldelete(RSIZE n, int kflag)
  * line is the magic header line always return TRUE; merging the last line
  * with the header line can be thought of as always being a successful
  * operation.  Even if nothing is done, this makes the kill buffer work
- * "right".  Easy cases can be done by shuffling data around.  Hard cases
+ * "right". If the mark is past the dot (actually, markline > dotline),
+ * decrease the markline accordingly to keep line numbers in sync.
+ * Easy cases can be done by shuffling data around.  Hard cases
  * require that lines be moved about in memory.  Return FALSE on error and
  * TRUE if all looks ok. We do not update w_dotline here, as deletes are done
  * after moves.
@@ -493,7 +508,10 @@ ldelnewline(void)
 	/* at the end of the buffer */
 	if (lp2 == curbp->b_headp)
 		return (TRUE);
+	/* Keep line counts in sync */
 	curwp->w_bufp->b_lines--;
+	if (curwp->w_markline > curwp->w_dotline)
+		curwp->w_markline--;
 	if (lp2->l_used <= lp1->l_size - lp1->l_used) {
 		bcopy(&lp2->l_text[0], &lp1->l_text[lp1->l_used], lp2->l_used);
 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {