Fix the line-resizing bug in scroll(). (Thanks to RDB for pointing

[sgt/putty] / terminal.c

diff --git a/terminal.c b/terminal.c
index cf55f8e..7fb2029 100644 (file)
--- a/terminal.c
+++ b/terminal.c
@@ -201,15 +201,40 @@ static FILE *lgfp = NULL;
 static void logtraffic(unsigned char c, int logmode);
 
 /*
+ * Resize a line to make it `cols' columns wide.
+ */
+unsigned long *resizeline(unsigned long *line, int cols)
+{
+    int i, oldlen;
+    unsigned long lineattrs;
+
+    if (line[0] != (unsigned long)cols) {
+       /*
+        * This line is the wrong length, which probably means it
+        * hasn't been accessed since a resize. Resize it now.
+        */
+       oldlen = line[0];
+       lineattrs = line[oldlen + 1];
+       line = srealloc(line, TSIZE * (2 + cols));
+       line[0] = cols;
+       for (i = oldlen; i < cols; i++)
+           line[i + 1] = ERASE_CHAR;
+       line[cols + 1] = lineattrs & LATTR_MODE;
+    }
+
+    return line;
+}
+
+/*
  * Retrieve a line of the screen or of the scrollback, according to
  * whether the y coordinate is non-negative or negative
  * (respectively).
  */
 unsigned long *lineptr(int y, int lineno)
 {
-    unsigned long *line, lineattrs;
+    unsigned long *line, *newline;
     tree234 *whichtree;
-    int i, treeindex, oldlen;
+    int treeindex;
 
     if (y >= 0) {
        whichtree = screen;
@@ -223,20 +248,10 @@ unsigned long *lineptr(int y, int lineno)
     /* We assume that we don't screw up and retrieve something out of range. */
     assert(line != NULL);
 
-    if (line[0] != cols) {
-       /*
-        * This line is the wrong length, which probably means it
-        * hasn't been accessed since a resize. Resize it now.
-        */
-       oldlen = line[0];
-       lineattrs = line[oldlen + 1];
+    newline = resizeline(line, cols);
+    if (newline != line) {
        delpos234(whichtree, treeindex);
-       line = srealloc(line, TSIZE * (2 + cols));
-       line[0] = cols;
-       for (i = oldlen; i < cols; i++)
-           line[i + 1] = ERASE_CHAR;
-       line[cols + 1] = lineattrs & LATTR_MODE;
-       addpos234(whichtree, line, treeindex);
+       addpos234(whichtree, newline, treeindex);
     }
 
     return line + 1;
@@ -568,6 +583,7 @@ static void scroll(int topline, int botline, int lines, int sb)
     if (lines < 0) {
        while (lines < 0) {
            line = delpos234(screen, botline);
+            line = resizeline(line, cols);
            for (i = 0; i < cols; i++)
                line[i + 1] = erase_char;
            line[cols + 1] = 0;
@@ -610,6 +626,7 @@ static void scroll(int topline, int botline, int lines, int sb)
                addpos234(scrollback, line, sblen);
                line = line2;
            }
+            line = resizeline(line, cols);
            for (i = 0; i < cols; i++)
                line[i + 1] = erase_char;
            line[cols + 1] = 0;