1 files changed, 30 insertions, 18 deletions

diff --git a/src/scroll.c b/src/scroll.c
index 3da236ca8a6..7cb683c4577 100644
--- a/src/scroll.c
+++ b/src/scroll.c
@@ -90,7 +90,7 @@ calculate_scrolling (struct frame *frame,
 		     /* matrix is of size window_size + 1 on each side.  */
 		     struct matrix_elt *matrix,
 		     int window_size, int lines_below,
-		     int *draw_cost, int *old_hash, int *new_hash,
+		     int *draw_cost, unsigned *old_hash, unsigned *new_hash,
 		     int free_at_end)
 {
   register int i, j;
@@ -245,18 +245,20 @@ do_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
 {
   struct matrix_elt *p;
   int i, j, k;
+  USE_SAFE_ALLOCA;
 
   /* True if we have set a terminal window with set_terminal_window.  */
   bool terminal_window_p = 0;
 
   /* A queue for line insertions to be done.  */
   struct queue { int count, pos; };
-  struct queue *queue_start
-    = alloca (current_matrix->nrows * sizeof *queue_start);
+  struct queue *queue_start;
+  SAFE_NALLOCA (queue_start, 1, current_matrix->nrows);
   struct queue *queue = queue_start;
 
-  char *retained_p = alloca (window_size * sizeof *retained_p);
-  int *copy_from = alloca (window_size * sizeof *copy_from);
+  char *retained_p = SAFE_ALLOCA (window_size);
+  int *copy_from;
+  SAFE_NALLOCA (copy_from, 1, window_size);
 
   /* Zero means line is empty.  */
   memset (retained_p, 0, window_size * sizeof (char));
@@ -378,6 +380,7 @@ do_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
 
   if (terminal_window_p)
     set_terminal_window (frame, 0);
+  SAFE_FREE ();
 }
 
 
@@ -427,7 +430,7 @@ calculate_direct_scrolling (struct frame *frame,
 			    struct matrix_elt *matrix,
 			    int window_size, int lines_below,
 			    int *draw_cost, int *old_draw_cost,
-			    int *old_hash, int *new_hash,
+			    unsigned *old_hash, unsigned *new_hash,
 			    int free_at_end)
 {
   register int i, j;
@@ -649,10 +652,12 @@ do_direct_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
 {
   struct matrix_elt *p;
   int i, j;
+  USE_SAFE_ALLOCA;
 
   /* A queue of deletions and insertions to be performed.  */
   struct alt_queue { int count, pos, window; };
-  struct alt_queue *queue_start = alloca (window_size * sizeof *queue_start);
+  struct alt_queue *queue_start;
+  SAFE_NALLOCA (queue_start, 1, window_size);
   struct alt_queue *queue = queue_start;
 
   /* True if a terminal window has been set with set_terminal_window.  */
@@ -667,11 +672,12 @@ do_direct_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
   bool write_follows_p = 1;
 
   /* For each row in the new matrix what row of the old matrix it is.  */
-  int *copy_from = alloca (window_size * sizeof *copy_from);
+  int *copy_from;
+  SAFE_NALLOCA (copy_from, 1, window_size);
 
   /* Non-zero for each row in the new matrix that is retained from the
      old matrix.  Lines not retained are empty.  */
-  char *retained_p = alloca (window_size * sizeof *retained_p);
+  char *retained_p = SAFE_ALLOCA (window_size);
 
   memset (retained_p, 0, window_size * sizeof (char));
 
@@ -787,6 +793,7 @@ do_direct_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
 
   if (terminal_window_p)
     set_terminal_window (frame, 0);
+  SAFE_FREE ();
 }
 
 
@@ -794,10 +801,11 @@ do_direct_scrolling (struct frame *frame, struct glyph_matrix *current_matrix,
 void
 scrolling_1 (struct frame *frame, int window_size, int unchanged_at_top,
 	     int unchanged_at_bottom, int *draw_cost, int *old_draw_cost,
-	     int *old_hash, int *new_hash, int free_at_end)
+	     unsigned *old_hash, unsigned *new_hash, int free_at_end)
 {
-  struct matrix_elt *matrix
-    = alloca ((window_size + 1) * (window_size + 1) * sizeof *matrix);
+  USE_SAFE_ALLOCA;
+  struct matrix_elt *matrix;
+  SAFE_NALLOCA (matrix, window_size + 1, window_size + 1);
 
   if (FRAME_SCROLL_REGION_OK (frame))
     {
@@ -817,6 +825,8 @@ scrolling_1 (struct frame *frame, int window_size, int unchanged_at_top,
                     frame->current_matrix, matrix, window_size,
 		    unchanged_at_top);
     }
+
+  SAFE_FREE ();
 }
 
 
@@ -829,12 +839,14 @@ scrolling_1 (struct frame *frame, int window_size, int unchanged_at_top,
 
 int
 scrolling_max_lines_saved (int start, int end,
-                           int *oldhash, int *newhash,
+                           unsigned *oldhash, unsigned *newhash,
                            int *cost)
 {
-  struct { int hash; int count; } lines[01000];
-  register int i, h;
-  register int matchcount = 0;
+  enum { LOG2_NLINES = 9 };
+  enum { NLINES = 1 << LOG2_NLINES };
+  struct { unsigned hash; int count; } lines[NLINES];
+  int i, h;
+  int matchcount = 0;
   int avg_length = 0;
   int threshold;
 
@@ -855,7 +867,7 @@ scrolling_max_lines_saved (int start, int end,
     {
       if (cost[i] > threshold)
 	{
-	  h = newhash[i] & 0777;
+	  h = newhash[i] & (NLINES - 1);
 	  lines[h].hash = newhash[i];
 	  lines[h].count++;
 	}
@@ -865,7 +877,7 @@ scrolling_max_lines_saved (int start, int end,
      matches between old lines and new.  */
   for (i = start; i < end; i++)
     {
-      h = oldhash[i] & 0777;
+      h = oldhash[i] & (NLINES - 1);
       if (oldhash[i] == lines[h].hash)
 	{
 	  matchcount++;