From d248b7041a7bf9b5c7b0cd79c8d4e9368e628944 Mon Sep 17 00:00:00 2001
From: Bill Kendrick <nbs@sonic.net>
Date: Sat, 25 Sep 2021 23:48:45 -0700
Subject: [PATCH] Avoid crashing if Magic returns NULL icon img

Was blindly calling thumbnail() on what came back
(which would be NULL if the image failed to load).

Also, mend bug where magic group arrays were being cleared
at the same time as stamp group ones; the latter is larger.
---
 src/tuxpaint.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/src/tuxpaint.c b/src/tuxpaint.c
index 2084daf20..ebc47d7d2 100644
--- a/src/tuxpaint.c
+++ b/src/tuxpaint.c
@@ -22,7 +22,7 @@
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   (See COPYING.txt)
 
-  June 14, 2002 - September 23, 2021
+  June 14, 2002 - September 25, 2021
 */
 
 #include "platform.h"
@@ -19454,6 +19454,7 @@ static void load_magic_plugins(void)
                               else
                                 {
                                   int j, group, idx;
+                                  SDL_Surface * icon_tmp;
 
                                   for (i = 0; i < n; i++)
                                     {
@@ -19509,17 +19510,27 @@ static void load_magic_plugins(void)
                                             magics[group][idx].mode = MODE_PAINT_WITH_PREVIEW;
                                           else
                                             magics[group][idx].mode = MODE_FULLSCREEN;
+   
+                                          icon_tmp = magic_funcs[num_plugin_files].get_icon(magic_api_struct, i);
+                                          if (icon_tmp != NULL)
+                                            { 
+                                              magics[group][idx].img_icon = thumbnail(icon_tmp, 40 * button_w / ORIGINAL_BUTTON_SIZE, 30 * button_h / ORIGINAL_BUTTON_SIZE, 1);
+                                              SDL_FreeSurface(icon_tmp);
     
-                                          magics[group][idx].img_icon =
-    					thumbnail(magic_funcs[num_plugin_files].get_icon(magic_api_struct, i), 40 * button_w / ORIGINAL_BUTTON_SIZE, 30 * button_h / ORIGINAL_BUTTON_SIZE, 1);
-    
-    #ifdef DEBUG
-                                          printf("-- %s\n", magics[group][idx].name);
-                                          printf("avail_modes = %d\n", magics[group][idx].avail_modes);
-    #endif
-    
-                                          num_magics[group]++;
-                                          num_magics_total++;
+#ifdef DEBUG
+                                              printf("-- %s\n", magics[group][idx].name);
+                                              printf("avail_modes = %d\n", magics[group][idx].avail_modes);
+#endif
+        
+                                              num_magics[group]++;
+                                              num_magics_total++;
+                                            }
+                                          else
+                                            {
+                                              fprintf(stderr, "Error: plugin %s mode # %d failed to load an icon\n",
+                                                fname, i, group);
+                                              fflush(stderr);
+                                            }
                                         }
                                       else
                                         {
@@ -25666,10 +25677,14 @@ static void claim_to_be_ready(void)
   for (i = 0; i < MAX_STAMP_GROUPS; i++)
     {
       stamp_scroll[i] = 0;
+    }
+  stamp_group = 0;              /* reset! */
+
+  for (i = 0; i < MAX_MAGIC_GROUPS; i++)
+    {
       magic_scroll[i] = 0;
       cur_magic[i] = 0;
     }
-  stamp_group = 0;              /* reset! */
   font_scroll = 0;
   tool_scroll = 0;
   eraser_scroll = 0;