--- pngvcrd.c.105	Thu Oct 14 05:43:08 1999
+++ pngvcrd.c	Tue Oct 19 08:09:02 1999
@@ -1182,7 +1182,7 @@
             {
                if (pixel_bytes == 3)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      _asm
                      {
@@ -1217,7 +1217,7 @@
                         EMMS
                      }
                   }
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      _asm
                      {
@@ -1288,20 +1290,20 @@
                         png_byte v[8];
                         int j;
 
-                        png_memcpy(v, sptr, pixel_bytes);
+                        png_memcpy(v, sptr, 3);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, 3);
+                           dp -= 3;
                         }
-                        sptr -= pixel_bytes;
+                        sptr -= 3;
                      }
                   }
                } /* end of pixel_bytes == 3 */
 
                else if (pixel_bytes == 1)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 2) << 2);
                      width -= width_mmx;
@@ -1368,7 +1370,7 @@
                         sptr--;
                      }
                   }
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 2) << 2);
                      width -= width_mmx;
@@ -1410,7 +1412,7 @@
                         sptr --;
                      }
                   }
-                  else //if ((pass == 4) || (pass == 5))
+                  else if (width) /* && ((pass == 4) || (pass == 5))) */
                   {
                      int width_mmx = ((width >> 3) << 3);
                      width -= width_mmx;
@@ -1457,7 +1459,7 @@
 
                else if (pixel_bytes == 2)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1);
                      width -= width_mmx;
@@ -1494,17 +1496,16 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
                      }
                   }
-
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1540,17 +1541,16 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
                      }
                   }
-
-                  else // pass == 4 or 5
+                  else if (width)  // pass == 4 or 5
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1581,12 +1581,12 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
                      }
                   }
@@ -1594,7 +1594,7 @@
 
                else if (pixel_bytes == 4)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1634,17 +1634,16 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
                      }
                   }
-
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1680,17 +1679,16 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
                      }
                   }
-
-                  else // pass == 4 or 5
+                  else if (width)  // pass == 4 or 5
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1724,12 +1722,12 @@
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
                      }
                   }
@@ -1742,13 +1740,13 @@
                   {
                      png_byte v[8];
                      int j;
-                     png_memcpy(v, sptr, pixel_bytes);
+                     png_memcpy(v, sptr, 6);
                      for (j = 0; j < png_pass_inc[pass]; j++)
                      {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
+                        png_memcpy(dp, v, 6);
+                        dp -= 6;
                      }
-                     sptr -= pixel_bytes;
+                     sptr -= 6;
                   }
                } /* end of pixel_bytes == 6 */