From fc5a96b6150e10abded6504e1d5983f0d01bee8c Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Fri, 15 Oct 2004 10:48:27 +0000
Subject: [PATCH] Fix many bugs in resizeline().

git-svn-id: svn://svn.tartarus.org/sgt/putty@4629 cda61777-01e9-0310-a592-d414129be87e
---
 terminal.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/terminal.c b/terminal.c
index 08574623..800a4f3f 100644
--- a/terminal.c
+++ b/terminal.c
@@ -845,9 +845,12 @@ static termline *decompressline(unsigned char *data, int *bytes_used)
  */
 static void resizeline(Terminal *term, termline *line, int cols)
 {
-    int i, oldlen;
+    int i, oldcols;
 
     if (line->cols != cols) {
+
+	oldcols = line->cols;
+
 	/*
 	 * This line is the wrong length, which probably means it
 	 * hasn't been accessed since a resize. Resize it now.
@@ -856,24 +859,36 @@ static void resizeline(Terminal *term, termline *line, int cols)
 	 * out in the resize (if we're shrinking the line) and
 	 * return their cc lists to the cc free list.
 	 */
-	for (i = cols; i < line->cols; i++)
+	for (i = cols; i < oldcols; i++)
 	    clear_cc(line, i);
 
 	/*
+	 * If we're shrinking the line, we now bodily move the
+	 * entire cc section from where it started to where it now
+	 * needs to be. (We have to do this before the resize, so
+	 * that the data we're copying is still there. However, if
+	 * we're expanding, we have to wait until _after_ the
+	 * resize so that the space we're copying into is there.)
+	 */
+	if (cols < oldcols)
+	    memmove(line->chars + cols, line->chars + oldcols,
+		    (line->size - line->cols) * TSIZE);
+
+	/*
 	 * Now do the actual resize, leaving the _same_ amount of
 	 * cc space as there was to begin with.
 	 */
-	oldlen = line->cols;
-	line->size += cols - oldlen;
+	line->size += cols - oldcols;
 	line->chars = sresize(line->chars, line->size, TTYPE);
 	line->cols = cols;
 
 	/*
-	 * Bodily move the entire cc section from where it started
-	 * to where it now needs to be.
+	 * If we're expanding the line, _now_ we move the cc
+	 * section.
 	 */
-	memmove(line->chars + line->cols, line->chars + oldlen,
-		(line->size - line->cols) * TSIZE);
+	if (cols > oldcols)
+	    memmove(line->chars + cols, line->chars + oldcols,
+		    (line->size - line->cols) * TSIZE);
 
 	/*
 	 * Go through what's left of the original line, and adjust
@@ -882,18 +897,18 @@ static void resizeline(Terminal *term, termline *line, int cols)
 	 * relative offsets within the cc block.) Also do the same
 	 * to the head of the cc_free list.
 	 */
-	for (i = 0; i < oldlen && i < line->cols; i++)
+	for (i = 0; i < oldcols && i < cols; i++)
 	    if (line->chars[i].cc_next)
-		line->chars[i].cc_next += cols - oldlen;
+		line->chars[i].cc_next += cols - oldcols;
 	if (line->cc_free)
-	    line->cc_free += cols - oldlen;
+	    line->cc_free += cols - oldcols;
 
 	/*
 	 * And finally fill in the new space with erase chars. (We
 	 * don't have to worry about cc lists here, because we
 	 * _know_ the erase char doesn't have one.)
 	 */
-	for (i = oldlen; i < cols; i++)
+	for (i = oldcols; i < cols; i++)
 	    line->chars[i] = term->basic_erase_char;
 
 	cc_check(line);		       /* XXX-REMOVE-BEFORE-RELEASE */
-- 
2.11.0