From a605cdf7008f856946cbf01193f4dffc3ee63fdb Mon Sep 17 00:00:00 2001
From: Solomon Peachy <pizza@shaftnet.org>
Date: Tue, 27 Oct 2020 11:14:23 -0400
Subject: [PATCH] Fix multiple potential null pointer dereferencess

GCC's optimizer thinks all of these _will_ fail at some point

Change-Id: I287eeb574162a5d3b3347654d25aa1f53e9f5563
---
 apps/gui/bitmap/list-skinned.c       | 17 ++++---
 apps/gui/skin_engine/skin_display.c  | 22 ++++++----
 apps/gui/skin_engine/skin_parser.c   | 54 ++++++++++++++++-------
 apps/gui/skin_engine/skin_render.c   | 66 ++++++++++++++++++----------
 apps/gui/skin_engine/skin_tokens.c   | 56 +++++++++++++----------
 apps/gui/statusbar-skinned.c         | 12 +++--
 apps/plugins/chessbox/chessbox_pgn.c | 14 ++++--
 apps/plugins/reversi/reversi-gui.c   |  7 +--
 8 files changed, 160 insertions(+), 88 deletions(-)

diff --git a/apps/gui/bitmap/list-skinned.c b/apps/gui/bitmap/list-skinned.c
index f0396263f3..c5429738ed 100644
--- a/apps/gui/bitmap/list-skinned.c
+++ b/apps/gui/bitmap/list-skinned.c
@@ -219,7 +219,9 @@ bool skinlist_draw(struct screen *display, struct gui_synclist *list)
         {
             int original_x, original_y;
             skin_viewport = SKINOFFSETTOPTR(get_skin_buffer(wps.data), viewport->data);
-            char *viewport_label = SKINOFFSETTOPTR(get_skin_buffer(wps.data), skin_viewport->label);
+            char *viewport_label = NULL;
+            if (skin_viewport)
+                viewport_label = SKINOFFSETTOPTR(get_skin_buffer(wps.data), skin_viewport->label);
             if (viewport->children == 0 || !viewport_label ||
                 (skin_viewport->label && strcmp(label, viewport_label))
                 )
@@ -254,13 +256,17 @@ bool skinlist_draw(struct screen *display, struct gui_synclist *list)
             while (imglist)
             {
                 struct wps_token *token = SKINOFFSETTOPTR(get_skin_buffer(wps.data), imglist->token);
-                struct gui_img *img = SKINOFFSETTOPTR(get_skin_buffer(wps.data), token->value.data);
-                img->display = -1;
+                struct gui_img *img = NULL;
+                if (token)
+                    img = SKINOFFSETTOPTR(get_skin_buffer(wps.data), token->value.data);
+                if (img)
+                    img->display = -1;
                 imglist = SKINOFFSETTOPTR(get_skin_buffer(wps.data), imglist->next);
             }
             struct skin_element** children = SKINOFFSETTOPTR(get_skin_buffer(wps.data), viewport->children);
-            skin_render_viewport(SKINOFFSETTOPTR(get_skin_buffer(wps.data), (intptr_t)children[0]),
-                                 &wps, skin_viewport, SKIN_REFRESH_ALL);
+            if (children && *children)
+                skin_render_viewport(SKINOFFSETTOPTR(get_skin_buffer(wps.data), (intptr_t)children[0]),
+                                     &wps, skin_viewport, SKIN_REFRESH_ALL);
             wps_display_images(&wps, &skin_viewport->vp);
             /* force disableing scroll because it breaks later */
             if (!is_selected)
@@ -278,4 +284,3 @@ bool skinlist_draw(struct screen *display, struct gui_synclist *list)
     current_drawing_line = list->selected_item;
     return true;
 }
-
diff --git a/apps/gui/skin_engine/skin_display.c b/apps/gui/skin_engine/skin_display.c
index c35b09eaac..4a3dcc2177 100644
--- a/apps/gui/skin_engine/skin_display.c
+++ b/apps/gui/skin_engine/skin_display.c
@@ -390,16 +390,20 @@ void wps_display_images(struct gui_wps *gwps, struct viewport* vp)
     while (list)
     {
         struct wps_token *token = SKINOFFSETTOPTR(get_skin_buffer(data), list->token);
-        struct gui_img *img = (struct gui_img*)SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
-        if (img->using_preloaded_icons && img->display >= 0)
-        {
-            screen_put_icon(display, img->x, img->y, img->display);
-        }
-        else if (img->loaded)
-        {
-            if (img->display >= 0)
+        struct gui_img *img = NULL;
+        if (token)
+            img = (struct gui_img*)SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
+        if (img) {
+            if (img->using_preloaded_icons && img->display >= 0)
             {
-                wps_draw_image(gwps, img, img->display, vp);
+                screen_put_icon(display, img->x, img->y, img->display);
+            }
+            else if (img->loaded)
+            {
+                if (img->display >= 0)
+                {
+                    wps_draw_image(gwps, img, img->display, vp);
+                }
             }
         }
         list = SKINOFFSETTOPTR(get_skin_buffer(data), list->next);
diff --git a/apps/gui/skin_engine/skin_parser.c b/apps/gui/skin_engine/skin_parser.c
index e1a8118190..b64bfc143c 100644
--- a/apps/gui/skin_engine/skin_parser.c
+++ b/apps/gui/skin_engine/skin_parser.c
@@ -183,13 +183,16 @@ void *skin_find_item(const char *label, enum skin_find_what what,
     {
         bool skip = false;
         struct wps_token *token = NULL;
+        itemlabel = NULL;
         if (!isvplist)
             token = SKINOFFSETTOPTR(databuf, list.linkedlist->token);
-        switch (what)
+        if (token)
+            switch (what)
         {
             case SKIN_FIND_UIVP:
             case SKIN_FIND_VP:
                 ret = SKINOFFSETTOPTR(databuf, list.vplist->data);
+                if (!ret) break;
                 if (((struct skin_viewport *)ret)->label == VP_DEFAULT_LABEL)
                     itemlabel = VP_DEFAULT_LABEL_STRING;
                 else
@@ -199,10 +202,12 @@ void *skin_find_item(const char *label, enum skin_find_what what,
                 break;
             case SKIN_FIND_IMAGE:
                 ret = SKINOFFSETTOPTR(databuf, token->value.data);
+                if (!ret) break;
                 itemlabel = SKINOFFSETTOPTR(databuf, ((struct gui_img *)ret)->label);
                 break;
 #ifdef HAVE_TOUCHSCREEN
             case SKIN_FIND_TOUCHREGION:
+                if (!ret) break;
                 ret = SKINOFFSETTOPTR(databuf, token->value.data);
                 itemlabel = SKINOFFSETTOPTR(databuf, ((struct touchregion *)ret)->label);
                 break;
@@ -210,6 +215,7 @@ void *skin_find_item(const char *label, enum skin_find_what what,
 #ifdef HAVE_SKIN_VARIABLES
             case SKIN_VARIABLE:
                 ret = SKINOFFSETTOPTR(databuf, token->value.data);
+                if (!ret) break;
                 itemlabel = SKINOFFSETTOPTR(databuf, ((struct skin_var *)ret)->label);
                 break;
 #endif
@@ -1708,23 +1714,30 @@ void skin_data_free_buflib_allocs(struct wps_data *wps_data)
 {
     if (wps_data->wps_loaded)
         skin_buffer = get_skin_buffer(wps_data);
+    if (!skin_buffer)
+        return;
+
 #ifndef __PCTOOL__
     struct skin_token_list *list = SKINOFFSETTOPTR(skin_buffer, wps_data->images);
     int *font_ids = SKINOFFSETTOPTR(skin_buffer, wps_data->font_ids);
     while (list)
     {
         struct wps_token *token = SKINOFFSETTOPTR(skin_buffer, list->token);
-        struct gui_img *img = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, token->value.data);
-        if (img->buflib_handle > 0)
+        struct gui_img *img = NULL;
+        if (token)
+            img = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, token->value.data);
+        if (img && img->buflib_handle > 0)
         {
             struct skin_token_list *imglist = SKINOFFSETTOPTR(skin_buffer, list->next);
-            core_free(img->buflib_handle);
 
+            core_free(img->buflib_handle);
             while (imglist)
             {
                 struct wps_token *freetoken = SKINOFFSETTOPTR(skin_buffer, imglist->token);
-                struct gui_img *freeimg = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, freetoken->value.data);
-                if (img->buflib_handle == freeimg->buflib_handle)
+                struct gui_img *freeimg = NULL;
+                if (freetoken)
+                    freeimg = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, freetoken->value.data);
+                if (freeimg && img->buflib_handle == freeimg->buflib_handle)
                     freeimg->buflib_handle = -1;
                 imglist = SKINOFFSETTOPTR(skin_buffer, imglist->next);
             }
@@ -1885,8 +1898,10 @@ static bool load_skin_bitmaps(struct wps_data *wps_data, char *bmpdir)
     while (list)
     {
         struct wps_token *token = SKINOFFSETTOPTR(skin_buffer, list->token);
+        if (!token) goto skip;
         struct gui_img *img = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, token->value.data);
-        if (!img->loaded)
+
+        if (img && !img->loaded)
         {
             if (img->using_preloaded_icons)
             {
@@ -1901,20 +1916,22 @@ static bool load_skin_bitmaps(struct wps_data *wps_data, char *bmpdir)
                 handle = load_skin_bmp(wps_data, &img->bm, bmpdir);
                 img->buflib_handle = handle;
                 img->loaded = img->buflib_handle >= 0;
+
                 if (img->loaded)
                 {
                     struct skin_token_list *imglist = SKINOFFSETTOPTR(skin_buffer, list->next);
-
                     img->subimage_height = img->bm.height / img->num_subimages;
                     while (imglist)
                     {
                         token = SKINOFFSETTOPTR(skin_buffer, imglist->token);
-                        img = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, token->value.data);
-                        if (!strcmp(path, img->bm.data))
-                        {
-                            img->loaded = true;
-                            img->buflib_handle = handle;
-                            img->subimage_height = img->bm.height / img->num_subimages;
+                        if (token) {
+                            img = (struct gui_img*)SKINOFFSETTOPTR(skin_buffer, token->value.data);
+                            if (img && !strcmp(path, img->bm.data))
+                            {
+                                img->loaded = true;
+                                img->buflib_handle = handle;
+                                img->subimage_height = img->bm.height / img->num_subimages;
+                            }
                         }
                         imglist = SKINOFFSETTOPTR(skin_buffer, imglist->next);
                     }
@@ -1923,6 +1940,7 @@ static bool load_skin_bitmaps(struct wps_data *wps_data, char *bmpdir)
                     retval = false;
             }
         }
+    skip:
         list = SKINOFFSETTOPTR(skin_buffer, list->next);
     }
 
@@ -1947,6 +1965,7 @@ static bool skin_load_fonts(struct wps_data *data)
         /* first, find the viewports that have a non-sys/ui-font font */
         struct skin_viewport *skin_vp =
                 SKINOFFSETTOPTR(skin_buffer, vp_list->data);
+        if (!skin_vp) continue;
         struct viewport *vp = &skin_vp->vp;
 
         font_id = skin_vp->parsed_fontid;
@@ -2507,9 +2526,10 @@ bool skin_data_load(enum screen_type screen, struct wps_data *wps_data,
     while (regions)
     {
         struct wps_token *token = SKINOFFSETTOPTR(skin_buffer, regions->token);
-        struct touchregion *r = SKINOFFSETTOPTR(skin_buffer, token->value.data);
-
-        if (r->action != ACTION_TOUCH_SCROLLBAR &&
+        struct touchregion *r = NULL;
+        if (token)
+            r = SKINOFFSETTOPTR(skin_buffer, token->value.data);
+        if (r && r->action != ACTION_TOUCH_SCROLLBAR &&
             r->action != ACTION_TOUCH_VOLUME)
         {
             user_touch_region_found = true;
diff --git a/apps/gui/skin_engine/skin_render.c b/apps/gui/skin_engine/skin_render.c
index ed2f783e7a..7f2dcab222 100644
--- a/apps/gui/skin_engine/skin_render.c
+++ b/apps/gui/skin_engine/skin_render.c
@@ -96,7 +96,7 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
                              struct skin_element *element, struct skin_viewport* skin_vp)
 {
     struct wps_token *token = (struct wps_token *)SKINOFFSETTOPTR(skin_buffer, element->data);
-
+    if (!token) return false;
     struct viewport *vp = &skin_vp->vp;
     struct wps_data *data = gwps->data;
     bool do_refresh = (element->tag->flags & info->refresh_type) > 0;
@@ -107,7 +107,9 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
         case SKIN_TOKEN_VIEWPORT_FGCOLOUR:
         {
             struct viewport_colour *col = SKINOFFSETTOPTR(skin_buffer, token->value.data);
+            if (!col) return false;
             struct viewport *vp = SKINOFFSETTOPTR(skin_buffer, col->vp);
+            if (!vp) return false;
             vp->fg_pattern = col->colour;
             skin_vp->fgbg_changed = true;
         }
@@ -115,7 +117,9 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
         case SKIN_TOKEN_VIEWPORT_BGCOLOUR:
         {
             struct viewport_colour *col = SKINOFFSETTOPTR(skin_buffer, token->value.data);
+            if (!col) return false;
             struct viewport *vp = SKINOFFSETTOPTR(skin_buffer, col->vp);
+            if (!vp) return false;
             vp->bg_pattern = col->colour;
             skin_vp->fgbg_changed = true;
         }
@@ -124,6 +128,7 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
         {
             struct line_desc *data = SKINOFFSETTOPTR(skin_buffer, token->value.data);
             struct line_desc *linedes = &info->line_desc;
+            if (!data || !linedes) return false;
             /* gradient colors are handled with a separate tag
              * (SKIN_TOKEN_VIEWPORT_GRADIENT_SETUP, see below). since it may
              * come before the text style tag color fields need to be preserved */
@@ -147,6 +152,7 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
         {
             struct gradient_config *cfg = SKINOFFSETTOPTR(skin_buffer, token->value.data);
             struct line_desc *linedes = &info->line_desc;
+            if (!cfg || !linedes) return false;
             linedes->text_color     = cfg->text;
             linedes->line_color     = cfg->start;
             linedes->line_end_color = cfg->end;
@@ -162,17 +168,19 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
             {
                 struct skin_viewport *skinvp = SKINOFFSETTOPTR(skin_buffer, viewport->data);
 
-                char *vplabel = SKINOFFSETTOPTR(skin_buffer, skinvp->label);
-                if (skinvp->label == VP_DEFAULT_LABEL)
-                    vplabel = VP_DEFAULT_LABEL_STRING;
-                if (vplabel && !skinvp->is_infovp &&
-                    !strcmp(vplabel, label))
-                {
-                    if (skinvp->hidden_flags&VP_DRAW_HIDDEN)
+                if (skinvp) {
+                    char *vplabel = SKINOFFSETTOPTR(skin_buffer, skinvp->label);
+                    if (skinvp->label == VP_DEFAULT_LABEL)
+                        vplabel = VP_DEFAULT_LABEL_STRING;
+                    if (vplabel && !skinvp->is_infovp &&
+                        !strcmp(vplabel, label))
                     {
-                        temp |= VP_DRAW_WASHIDDEN;
+                        if (skinvp->hidden_flags&VP_DRAW_HIDDEN)
+                        {
+                            temp |= VP_DRAW_WASHIDDEN;
+                        }
+                        skinvp->hidden_flags = temp;
                     }
-                    skinvp->hidden_flags = temp;
                 }
                 viewport = SKINOFFSETTOPTR(skin_buffer, viewport->next);
             }
@@ -195,12 +203,13 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
             {
                 struct draw_rectangle *rect =
                         SKINOFFSETTOPTR(skin_buffer, token->value.data);
+                if (!rect) break;
 #ifdef HAVE_LCD_COLOR
                 if (rect->start_colour != rect->end_colour &&
-                        gwps->display->screen_type == SCREEN_MAIN)
+                    gwps->display->screen_type == SCREEN_MAIN)
                 {
                     gwps->display->gradient_fillrect(rect->x, rect->y, rect->width,
-                            rect->height, rect->start_colour, rect->end_colour);
+                        rect->height, rect->start_colour, rect->end_colour);
                 }
                 else
 #endif
@@ -210,7 +219,7 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
                     vp->fg_pattern = rect->start_colour;
 #endif
                     gwps->display->fillrect(rect->x, rect->y, rect->width,
-                            rect->height);
+                        rect->height);
 #if LCD_DEPTH > 1
                     vp->fg_pattern = backup;
 #endif
@@ -245,6 +254,7 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
         case SKIN_TOKEN_IMAGE_DISPLAY_9SEGMENT:
         {
             struct image_display *id = SKINOFFSETTOPTR(skin_buffer, token->value.data);
+            if (!id) break;
             const char* label = SKINOFFSETTOPTR(skin_buffer, id->label);
             struct gui_img *img = skin_find_item(label,SKIN_FIND_IMAGE, data);
             if (img && img->loaded)
@@ -313,7 +323,6 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
                 skin_render_playlistviewer(SKINOFFSETTOPTR(skin_buffer, token->value.data), gwps,
                                            info->skin_vp, info->refresh_type);
             break;
-
 #ifdef HAVE_SKIN_VARIABLES
         case SKIN_TOKEN_VAR_SET:
             {
@@ -374,19 +383,21 @@ static void do_tags_in_hidden_conditional(struct skin_element* branch,
                 {
                     do_tags_in_hidden_conditional(get_child(child->children, i), info);
                 }
-                child = SKINOFFSETTOPTR(skin_buffer, child->next);
-                continue;
+                goto skip;
             }
             else if (child->type != TAG || !SKINOFFSETTOPTR(skin_buffer, child->data))
             {
-                child = SKINOFFSETTOPTR(skin_buffer, child->next);
-                continue;
+                goto skip;
             }
+
             token = (struct wps_token *)SKINOFFSETTOPTR(skin_buffer, child->data);
+
             /* clear all pictures in the conditional and nested ones */
             if (token->type == SKIN_TOKEN_IMAGE_PRELOAD_DISPLAY)
             {
                 struct image_display *id = SKINOFFSETTOPTR(skin_buffer, token->value.data);
+                if (!id) goto skip;
+
                 struct gui_img *img = skin_find_item(SKINOFFSETTOPTR(skin_buffer, id->label),
                                                      SKIN_FIND_IMAGE, data);
                 clear_image_pos(gwps, img);
@@ -404,6 +415,7 @@ static void do_tags_in_hidden_conditional(struct skin_element* branch,
                      viewport = SKINOFFSETTOPTR(skin_buffer, viewport->next))
                 {
                     struct skin_viewport *skin_viewport = SKINOFFSETTOPTR(skin_buffer, viewport->data);
+                    if (!skin_viewport) continue;
                     char *vplabel = SKINOFFSETTOPTR(skin_buffer, skin_viewport->label);
                     if (skin_viewport->label == VP_DEFAULT_LABEL)
                         vplabel = VP_DEFAULT_LABEL_STRING;
@@ -451,6 +463,7 @@ static void do_tags_in_hidden_conditional(struct skin_element* branch,
                         playback_current_aa_hid(data->playback_aa_slot), true);
             }
 #endif
+        skip:
             child = SKINOFFSETTOPTR(skin_buffer, child->next);
         }
     }
@@ -517,6 +530,7 @@ static bool skin_render_line(struct skin_element* line, struct skin_draw_info *i
         {
             case CONDITIONAL:
                 conditional = SKINOFFSETTOPTR(skin_buffer, child->data);
+                if (!conditional) break;
                 last_value = conditional->last_value;
                 value = evaluate_conditional(info->gwps, info->offset,
                                              conditional, child->children_count);
@@ -623,7 +637,8 @@ static int get_subline_timeout(struct gui_wps *gwps, struct skin_element* line)
             element->tag->type == SKIN_TOKEN_SUBLINE_TIMEOUT )
         {
             token = SKINOFFSETTOPTR(skin_buffer, element->data);
-            return token->value.i;
+            if (token)
+                return token->value.i;
         }
         else if (element->type == CONDITIONAL)
         {
@@ -726,8 +741,11 @@ void skin_render_viewport(struct skin_element* viewport, struct gui_wps *gwps,
     while (imglist)
     {
         struct wps_token *token = SKINOFFSETTOPTR(skin_buffer, imglist->token);
-        struct gui_img *img = (struct gui_img *)SKINOFFSETTOPTR(skin_buffer, token->value.data);
-        img->display = -1;
+        if (token) {
+            struct gui_img *img = (struct gui_img *)SKINOFFSETTOPTR(skin_buffer, token->value.data);
+            if (img)
+                img->display = -1;
+        }
         imglist = SKINOFFSETTOPTR(skin_buffer, imglist->next);
     }
 
@@ -756,7 +774,6 @@ void skin_render_viewport(struct skin_element* viewport, struct gui_wps *gwps,
         align->center = NULL;
         align->right = NULL;
 
-
         if (line->type == LINE_ALTERNATOR)
             func = skin_render_alternator;
         else if (line->type == LINE)
@@ -819,9 +836,10 @@ void skin_render(struct gui_wps *gwps, unsigned refresh_mode)
             display->clear_viewport();
         }
     }
-
     viewport = SKINOFFSETTOPTR(skin_buffer, data->tree);
+    if (!viewport) return;
     skin_viewport = SKINOFFSETTOPTR(skin_buffer, viewport->data);
+    if (!skin_viewport) return;
     label = SKINOFFSETTOPTR(skin_buffer, skin_viewport->label);
     if (skin_viewport->label == VP_DEFAULT_LABEL)
         label = VP_DEFAULT_LABEL_STRING;
@@ -833,8 +851,10 @@ void skin_render(struct gui_wps *gwps, unsigned refresh_mode)
          viewport;
          viewport = SKINOFFSETTOPTR(skin_buffer, viewport->next))
     {
+
         /* SETUP */
         skin_viewport = SKINOFFSETTOPTR(skin_buffer, viewport->data);
+        if (!skin_viewport) continue;
         unsigned vp_refresh_mode = refresh_mode;
 #if (LCD_DEPTH > 1) || (defined(HAVE_REMOTE_LCD) && LCD_REMOTE_DEPTH > 1)
         if (skin_viewport->output_to_backdrop_buffer)
diff --git a/apps/gui/skin_engine/skin_tokens.c b/apps/gui/skin_engine/skin_tokens.c
index db9a9e694b..b86c664d7e 100644
--- a/apps/gui/skin_engine/skin_tokens.c
+++ b/apps/gui/skin_engine/skin_tokens.c
@@ -163,7 +163,7 @@ const char *get_cuesheetid3_token(struct wps_token *token, struct mp3entry *id3,
     struct cuesheet *cue = id3?id3->cuesheet:NULL;
     if (!cue || !cue->curr_track)
         return NULL;
-    
+
     struct cue_track_info *track = cue->curr_track;
     if (offset_tracks)
     {
@@ -185,7 +185,7 @@ const char *get_cuesheetid3_token(struct wps_token *token, struct mp3entry *id3,
         case SKIN_TOKEN_METADATA_TRACK_TITLE:
             return *track->title ? track->title : NULL;
         case SKIN_TOKEN_METADATA_TRACK_NUMBER:
-            snprintf(buf, buf_size, "%d/%d",  
+            snprintf(buf, buf_size, "%d/%d",
                      cue->curr_track_idx+offset_tracks+1, cue->track_count);
             return buf;
         default:
@@ -200,7 +200,7 @@ static const char* get_filename_token(struct wps_token *token, char* filename,
     if (filename)
     {
         switch (token->type)
-        {        
+        {
             case SKIN_TOKEN_FILE_PATH:
                 return filename;
             case SKIN_TOKEN_FILE_NAME:
@@ -478,7 +478,7 @@ const char *get_radio_token(struct wps_token *token, int preset_offset,
                 {
                     *intval = val;
                 }
-                else 
+                else
                 {
                     *intval = 1+(limit-1)*(val-min)/(max-1-min);
                 }
@@ -514,7 +514,7 @@ const char *get_radio_token(struct wps_token *token, int preset_offset,
             return buf;
         }
         case SKIN_TOKEN_PRESET_COUNT:
-            snprintf(buf, buf_size, "%d", radio_preset_count());        
+            snprintf(buf, buf_size, "%d", radio_preset_count());
             if (intval)
                 *intval = radio_preset_count();
             return buf;
@@ -580,7 +580,7 @@ static const char* NOINLINE get_lif_token_value(struct gui_wps *gwps,
     int b;
     bool number_set = true;
     struct wps_token *liftoken = SKINOFFSETTOPTR(get_skin_buffer(gwps->data), lif->token);
-    const char* out_text = get_token_value(gwps, liftoken, offset, buf, buf_size, &a);            
+    const char* out_text = get_token_value(gwps, liftoken, offset, buf, buf_size, &a);
     if (a == -1 && liftoken->type != SKIN_TOKEN_VOLUME)
     {
         a = (out_text && *out_text) ? 1 : 0;
@@ -610,10 +610,13 @@ static const char* NOINLINE get_lif_token_value(struct gui_wps *gwps,
             char temp_buf[MAX_PATH];
             const char *outb;
             struct skin_element *element = SKINOFFSETTOPTR(get_skin_buffer(gwps->data), lif->operand.data.code);
+            if (!element) return NULL;
             struct wps_token *token = SKINOFFSETTOPTR(get_skin_buffer(gwps->data), element->data);
             b = lif->num_options;
+
             outb = get_token_value(gwps, token, offset, temp_buf,
-                                   sizeof(temp_buf), &b);            
+                                   sizeof(temp_buf), &b);
+
             if (b == -1 && liftoken->type != SKIN_TOKEN_VOLUME)
             {
                 if (!out_text || !outb)
@@ -631,7 +634,7 @@ static const char* NOINLINE get_lif_token_value(struct gui_wps *gwps,
         case DEFAULT:
             break;
     }
-            
+
     switch (lif->op)
     {
         case IF_EQUALS:
@@ -666,10 +669,12 @@ const char *get_token_value(struct gui_wps *gwps,
 {
     if (!gwps)
         return NULL;
+    if (!token)
+        return NULL;
 
     struct wps_data *data = gwps->data;
     struct wps_state *state = skin_get_global_state();
-    struct mp3entry *id3; /* Think very carefully about using this. 
+    struct mp3entry *id3; /* Think very carefully about using this.
                              maybe get_id3_token() is the better place? */
     const char *out_text = NULL;
     char *filename = NULL;
@@ -680,7 +685,7 @@ const char *get_token_value(struct gui_wps *gwps,
     id3 = get_mp3entry_from_offset(token->next? 1: offset, &filename);
     if (id3)
         filename = id3->path;
-        
+
 #if CONFIG_RTC
     struct tm* tm = NULL;
 
@@ -702,10 +707,10 @@ const char *get_token_value(struct gui_wps *gwps,
         limit = *intval;
         *intval = -1;
     }
-    
+
     if (id3 && id3 == state->id3 && id3->cuesheet )
     {
-        out_text = get_cuesheetid3_token(token, id3, 
+        out_text = get_cuesheetid3_token(token, id3,
                                          token->next?1:offset, buf, buf_size);
         if (out_text)
             return out_text;
@@ -734,6 +739,7 @@ const char *get_token_value(struct gui_wps *gwps,
             char *skinbuffer = get_skin_buffer(data);
             struct skin_element *element =
                     SKINOFFSETTOPTR(skinbuffer, token->value.data);
+            if (!element || !element->params) return NULL;
             struct skin_tag_parameter* params =
                     SKINOFFSETTOPTR(skinbuffer, element->params);
             struct skin_tag_parameter* thistag;
@@ -742,6 +748,7 @@ const char *get_token_value(struct gui_wps *gwps,
                 thistag = &params[i];
                 struct skin_element *tokenelement =
                         SKINOFFSETTOPTR(skinbuffer, thistag->data.code);
+                if (!tokenelement) return NULL;
                 out_text  =  get_token_value(gwps,
                         SKINOFFSETTOPTR(skinbuffer, tokenelement->data),
                         offset, buf, buf_size, intval);
@@ -753,10 +760,12 @@ const char *get_token_value(struct gui_wps *gwps,
             return truecount ? "true" : NULL;
         }
         break;
+
         case SKIN_TOKEN_SUBSTRING:
         {
             struct substring *ss = SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
-            const char *token_val = get_token_value(gwps, 
+            if (!ss) return NULL;
+            const char *token_val = get_token_value(gwps,
                             SKINOFFSETTOPTR(get_skin_buffer(data), ss->token), offset,
                                                     buf, buf_size, intval);
             if (token_val)
@@ -788,13 +797,13 @@ const char *get_token_value(struct gui_wps *gwps,
                 if (ss->expect_number &&
                     intval && (buf[0] >= '0' && buf[0] <= '9'))
                     *intval = atoi(buf) + 1; /* so 0 is the first item */
-                    
+
                 return buf;
             }
             return NULL;
         }
-        break;        
-            
+        break;
+
         case SKIN_TOKEN_CHARACTER:
             if (token->value.c == '\n')
                 return NULL;
@@ -802,7 +811,7 @@ const char *get_token_value(struct gui_wps *gwps,
 
         case SKIN_TOKEN_STRING:
             return (char*)SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
-            
+
         case SKIN_TOKEN_TRANSLATEDSTRING:
             return (char*)P2STR(ID2P(token->value.i));
 
@@ -821,6 +830,7 @@ const char *get_token_value(struct gui_wps *gwps,
         case SKIN_TOKEN_LIST_ITEM_TEXT:
         {
             struct listitem *li = (struct listitem *)SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
+            if (!li) return NULL;
             return skinlist_get_item_text(li->offset, li->wrap, buf, buf_size);
         }
         case SKIN_TOKEN_LIST_ITEM_ROW:
@@ -843,6 +853,7 @@ const char *get_token_value(struct gui_wps *gwps,
         case SKIN_TOKEN_LIST_ITEM_ICON:
         {
             struct listitem *li = (struct listitem *)SKINOFFSETTOPTR(get_skin_buffer(data), token->value.data);
+            if (!li) return NULL;
             int icon = skinlist_get_item_icon(li->offset, li->wrap);
             if (intval)
                 *intval = icon;
@@ -905,11 +916,12 @@ const char *get_token_value(struct gui_wps *gwps,
                 if (in_radio_screen() || (get_radio_status() != FMRADIO_OFF))
                 {
                     struct skin_albumart *aa = SKINOFFSETTOPTR(get_skin_buffer(data), data->albumart);
+                    if (!aa) return NULL;
                     struct dim dim = {aa->width, aa->height};
                     handle = radio_get_art_hid(&dim);
                 }
 #endif
-                if (handle >= 0)    
+                if (handle >= 0)
                     return "C";
             }
             return NULL;
@@ -1009,7 +1021,7 @@ const char *get_token_value(struct gui_wps *gwps,
             int mode = 1; /* stop */
             if (status == STATUS_PLAY)
                 mode = 2; /* play */
-            if (state->is_fading || 
+            if (state->is_fading ||
                (status == STATUS_PAUSE  && !status_get_ffmode()))
                 mode = 3; /* pause */
             else
@@ -1336,13 +1348,13 @@ const char *get_token_value(struct gui_wps *gwps,
                                           token->value.i))
                 return "v";
             return NULL;
-            
         case SKIN_TOKEN_LASTTOUCH:
             {
 #ifdef HAVE_TOUCHSCREEN
             unsigned int last_touch = touchscreen_last_touch();
             char *skin_base = get_skin_buffer(data);
             struct touchregion_lastpress *data = SKINOFFSETTOPTR(skin_base, token->value.data);
+            if (!data) return NULL;
             struct touchregion *region = SKINOFFSETTOPTR(skin_base, data->region);
             if (region)
                 last_touch = region->last_press;
@@ -1669,10 +1681,8 @@ const char *get_token_value(struct gui_wps *gwps,
             }
             return NULL;
 #endif
-
         default:
             return NULL;
     }
+
 }
-
-
diff --git a/apps/gui/statusbar-skinned.c b/apps/gui/statusbar-skinned.c
index f8e06c2b5d..9b10ad4dce 100644
--- a/apps/gui/statusbar-skinned.c
+++ b/apps/gui/statusbar-skinned.c
@@ -86,14 +86,15 @@ int sb_preproccess(enum screen_type screen, struct wps_data *data)
 int sb_postproccess(enum screen_type screen, struct wps_data *data)
 {
     if (data->wps_loaded)
-    {  
+    {
         /* hide the sb's default viewport because it has nasty effect with stuff
         * not part of the statusbar,
         * hence .sbs's without any other vps are unsupported*/
         struct skin_viewport *vp = skin_find_item(VP_DEFAULT_LABEL_STRING, SKIN_FIND_VP, data);
         struct skin_element *tree = SKINOFFSETTOPTR(get_skin_buffer(data), data->tree);
-        struct skin_element *next_vp = SKINOFFSETTOPTR(get_skin_buffer(data), tree->next);
-        
+        struct skin_element *next_vp = NULL;
+        if (tree) next_vp = SKINOFFSETTOPTR(get_skin_buffer(data), tree->next);
+
         if (vp)
         {
             if (!next_vp)
@@ -132,9 +133,12 @@ struct viewport *sb_skin_get_info_vp(enum screen_type screen)
         viewportmanager_theme_enable(screen, false, NULL);
         viewportmanager_theme_undo(screen, true);
     }
-    label = SKINOFFSETTOPTR(get_skin_buffer(data), infovp_label[screen]);
     if (infovp_label[screen] == VP_DEFAULT_LABEL)
         label = VP_DEFAULT_LABEL_STRING;
+    else
+        label = SKINOFFSETTOPTR(get_skin_buffer(data), infovp_label[screen]);
+    if (!label)
+        return NULL;
     vp = skin_find_item(label, SKIN_FIND_UIVP, data);
     if (!vp)
         return NULL;
diff --git a/apps/plugins/chessbox/chessbox_pgn.c b/apps/plugins/chessbox/chessbox_pgn.c
index 40e88e500b..0d9da441b1 100644
--- a/apps/plugins/chessbox/chessbox_pgn.c
+++ b/apps/plugins/chessbox/chessbox_pgn.c
@@ -623,6 +623,7 @@ struct pgn_game_node* pgn_list_games(const char* filename){
             /* a new game header is found */
             if (line_buffer[0] == '['){
                 temp_node = (struct pgn_game_node *)pl_malloc(sizeof size_node);
+                if (!temp_node) return NULL;
                 temp_node->next_node = NULL;
                 if (curr_node == NULL) {
                     first_game = curr_node = temp_node;
@@ -773,9 +774,11 @@ void pgn_parse_game(const char* filename,
      */
     if (first_ply != NULL){
         temp_ply = (struct pgn_ply_node *)pl_malloc(sizeof size_ply);
-        temp_ply->player = neutral;
-        temp_ply->prev_node = curr_node;
-        curr_node->next_node = temp_ply;
+        if (temp_ply) {
+            temp_ply->player = neutral;
+            temp_ply->prev_node = curr_node;
+            curr_node->next_node = temp_ply;
+        }
     }
     selected_game->first_ply = first_ply;
 
@@ -793,6 +796,7 @@ struct pgn_game_node* pgn_init_game(void){
 
     /* create an "end of game" dummy ply and assign defaults */
     ply = (struct pgn_ply_node *)pl_malloc(sizeof ply_size);
+    if (!ply) return NULL;
     ply->player = neutral;
     ply->pgn_text[0] = '\0';
     ply->prev_node = NULL;
@@ -800,6 +804,8 @@ struct pgn_game_node* pgn_init_game(void){
 
     /* create the game and assign defaults */
     game = (struct pgn_game_node *)pl_malloc(sizeof game_size);
+    if (!game) return NULL;
+
     game->game_number = 0;
     rb->strcpy(game->white_player,"Player");
     rb->strcpy(game->black_player,"GnuChess");
@@ -823,6 +829,7 @@ void pgn_append_ply(struct pgn_game_node* game,
     struct pgn_ply_node ply_size, *ply, *temp;
 
     ply = (struct pgn_ply_node *)pl_malloc(sizeof ply_size);
+    if (!ply) return;
     ply->player = ply_player;
     ply->column_from = move_buffer[0] - 'a';
     ply->row_from = move_buffer[1] - '1';
@@ -847,6 +854,7 @@ void pgn_append_ply(struct pgn_game_node* game,
     } else {
         temp->prev_node->next_node = ply;
     }
+
     temp->prev_node = ply;
 }
 
diff --git a/apps/plugins/reversi/reversi-gui.c b/apps/plugins/reversi/reversi-gui.c
index aca54a1ea3..74dd98b676 100644
--- a/apps/plugins/reversi/reversi-gui.c
+++ b/apps/plugins/reversi/reversi-gui.c
@@ -637,12 +637,13 @@ enum plugin_status plugin_start(const void *parameter) {
             draw_screen = false;
         }
         switch(cur_player) {
-            case BLACK:
-                cur_strategy = black_strategy;
-                break;
             case WHITE:
                 cur_strategy = white_strategy;
                 break;
+            case BLACK:
+            default:
+                cur_strategy = black_strategy;
+                break;
         }
 
         if(cur_strategy->is_robot && !game_finished) {