(verify_charstarts): New function.

(scroll_frame_lines): When updating charstarts,
treat all columns alike--don't zero out any.
Fix end tests of loops over i.

(adjust_window_charstarts): Fix typo.

1 files changed, 71 insertions, 39 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index 82d5616af4a..68e9423fcbd 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -607,6 +607,7 @@ scroll_frame_lines (frame, from, end, amount, newpos)
   register struct frame_glyphs *current_frame
     = FRAME_CURRENT_GLYPHS (frame);
   int pos_adjust;
+  int width = FRAME_WIDTH (frame);
 
   if (!line_ins_del_ok)
     return 0;
@@ -631,40 +632,41 @@ scroll_frame_lines (frame, from, end, amount, newpos)
                      sizeof (int *) * (end + amount - from),
                      amount * sizeof (int *));
 
+      safe_bcopy (current_frame->used + from,
+                  current_frame->used + from + amount,
+                  (end - from) * sizeof current_frame->used[0]);
+
+      safe_bcopy (current_frame->highlight + from,
+                  current_frame->highlight + from + amount,
+                  (end - from) * sizeof current_frame->highlight[0]);
+
+      safe_bcopy (current_frame->enable + from,
+                  current_frame->enable + from + amount,
+                  (end - from) * sizeof current_frame->enable[0]);
+
       /* Adjust the lines by an amount
          that puts the first of them at NEWPOS.  */
-      pos_adjust = newpos - current_frame->charstarts[i][0];
+      pos_adjust = newpos - current_frame->charstarts[from + amount][0];
 
       /* Offset each char position in the charstarts lines we moved
          by pos_adjust.  */
-      for (i = from + amount; i < end; i++)
+      for (i = from + amount; i < end + amount; i++)
         {
           int *line = current_frame->charstarts[i];
           int col;
-          for (col = 0; col < current_frame->used[i]; col++)
-            line[col] += pos_adjust;
+          for (col = 0; col < width; col++)
+            if (line[col] > 0)
+              line[col] += pos_adjust;
         }
-      for (i = from; i <= from + amount; i++)
+      for (i = from; i < from + amount; i++)
         {
           int *line = current_frame->charstarts[i];
           int col;
           line[0] = -1;
-          for (col = 0; col < current_frame->used[i]; col++)
+          for (col = 0; col < width; col++)
             line[col] = 0;
         }
 
-      safe_bcopy (current_frame->used + from,
-                  current_frame->used + from + amount,
-                  (end - from) * sizeof current_frame->used[0]);
-
-      safe_bcopy (current_frame->highlight + from,
-                  current_frame->highlight + from + amount,
-                  (end - from) * sizeof current_frame->highlight[0]);
-
-      safe_bcopy (current_frame->enable + from,
-                  current_frame->enable + from + amount,
-                  (end - from) * sizeof current_frame->enable[0]);
-
       /* Mark the lines made empty by scrolling as enabled, empty and
          normal video.  */
       bzero (current_frame->used + from,
@@ -726,9 +728,21 @@ scroll_frame_lines (frame, from, end, amount, newpos)
                      sizeof (int *) * (end - from - amount),
                      amount * sizeof (int *));
 
+      safe_bcopy (current_frame->used + from,
+                  current_frame->used + from + amount,
+                  (end - from) * sizeof current_frame->used[0]);
+
+      safe_bcopy (current_frame->highlight + from,
+                  current_frame->highlight + from + amount,
+                  (end - from) * sizeof current_frame->highlight[0]);
+
+      safe_bcopy (current_frame->enable + from,
+                  current_frame->enable + from + amount,
+                  (end - from) * sizeof current_frame->enable[0]);
+
       /* Adjust the lines by an amount
          that puts the first of them at NEWPOS.  */
-      pos_adjust = newpos - current_frame->charstarts[i][0];
+      pos_adjust = newpos - current_frame->charstarts[from + amount][0];
 
       /* Offset each char position in the charstarts lines we moved
          by pos_adjust.  */
@@ -736,30 +750,19 @@ scroll_frame_lines (frame, from, end, amount, newpos)
         {
           int *line = current_frame->charstarts[i];
           int col;
-          for (col = 0; col < current_frame->used[i]; col++)
-            line[col] += pos_adjust;
+          for (col = 0; col < width; col++)
+            if (line[col] > 0)
+              line[col] += pos_adjust;
         }
-      for (i = end + amount; i <= end; i++)
+      for (i = end + amount; i < end; i++)
         {
           int *line = current_frame->charstarts[i];
           int col;
           line[0] = -1;
-          for (col = 0; col < current_frame->used[i]; col++)
+          for (col = 0; col < width; col++)
             line[col] = 0;
         }
 
-      safe_bcopy (current_frame->used + from,
-                  current_frame->used + from + amount,
-                  (end - from) * sizeof current_frame->used[0]);
-
-      safe_bcopy (current_frame->highlight + from,
-                  current_frame->highlight + from + amount,
-                  (end - from) * sizeof current_frame->highlight[0]);
-
-      safe_bcopy (current_frame->enable + from,
-                  current_frame->enable + from + amount,
-                  (end - from) * sizeof current_frame->enable[0]);
-
       /* Mark the lines made empty by scrolling as enabled, empty and
          normal video.  */
       bzero (current_frame->used + end + amount,
@@ -906,7 +909,7 @@ preserve_my_columns (w)
 #endif
 
 /* Adjust by ADJUST the charstart values in window W
-   before vpos VPOS, which counts relative to the frame
+   after vpos VPOS, which counts relative to the frame
    (not relative to W itself).  */
 
 void
@@ -917,11 +920,11 @@ adjust_window_charstarts (w, vpos, adjust)
 {
   int left = XFASTINT (w->left);
   int top = XFASTINT (w->top);
-  int right = left + window_internal_height (w);
-  int height = window_internal_height (w);
+  int right = left + window_internal_width (w);
+  int bottom = top + window_internal_height (w);
   int i;
 
-  for (i = vpos + 1; i < top + height; i++)
+  for (i = vpos + 1; i < bottom; i++)
     {
       int *charstart
         = FRAME_CURRENT_GLYPHS (XFRAME (WINDOW_FRAME (w)))->charstarts[i];
@@ -931,6 +934,35 @@ adjust_window_charstarts (w, vpos, adjust)
           charstart[j] += adjust;
     }
 }
+
+verify_charstarts (w)
+     struct window *w;
+{
+  FRAME_PTR f = XFRAME (WINDOW_FRAME (w));
+  int i;
+  int top = XFASTINT (w->top);
+  int bottom = top + window_internal_height (w);
+  int left = XFASTINT (w->left);
+  int right = left + window_internal_width (w);
+  int next_line;
+
+  for (i = top; i < bottom; i++)
+    {
+      int j;
+      int last;
+      int *charstart
+        = FRAME_CURRENT_GLYPHS (XFRAME (WINDOW_FRAME (w)))->charstarts[i];
+
+      if (i != top)
+        if (charstart[left] != next_line)
+          abort ();
+
+      for (j = left; j < right; j++)
+        if (charstart[j] > 0)
+          last = charstart[j];
+      next_line = last + (BUF_ZV (XBUFFER (w->buffer)) != last);
+    }
+}
 
 /* On discovering that the redisplay for a window was no good,
    cancel the columns of that window, so that when the window is