Fix FS#1159 - stack overflow in the skin engine when there is too many nested conditionals

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28167 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 69 insertions, 62 deletions

diff --git a/apps/gui/skin_engine/skin_render.c b/apps/gui/skin_engine/skin_render.c
index 4fbd550..baa1f82 100644
--- a/apps/gui/skin_engine/skin_render.c
+++ b/apps/gui/skin_engine/skin_render.c
@@ -382,11 +382,9 @@ static bool skin_render_line(struct skin_element* line, struct skin_draw_info *i
     struct skin_element *child = line->children[0];
     struct conditional *conditional;
     skin_render_func func = skin_render_line;
-    char tempbuf[128];
     int old_refresh_mode = info->refresh_type;
     while (child)
     {
-        tempbuf[0] = '\0';
         switch (child->type)
         {
             case CONDITIONAL:
@@ -447,6 +445,7 @@ static bool skin_render_line(struct skin_element* line, struct skin_draw_info *i
                 }
                 if (!do_non_text_tags(info->gwps, info, child, &info->skin_vp->vp))
                 {
+                    static char tempbuf[128];
                     const char *value = get_token_value(info->gwps, child->data,
                                                         info->offset, tempbuf,
                                                         sizeof(tempbuf), NULL);
diff --git a/apps/gui/skin_engine/skin_tokens.c b/apps/gui/skin_engine/skin_tokens.c
index 1bfc861..df4e7d9 100644
--- a/apps/gui/skin_engine/skin_tokens.c
+++ b/apps/gui/skin_engine/skin_tokens.c
@@ -552,6 +552,73 @@ static struct mp3entry* get_mp3entry_from_offset(int offset, char **filename)
     return pid3;
 }
 
+static const char* get_lif_token_value(struct gui_wps *gwps,
+                                       struct logical_if *lif,
+                                       int offset, char *buf, int buf_size)
+{
+    int a = lif->num_options;
+    int b;
+    const char* out_text = get_token_value(gwps, lif->token, offset,
+                                           buf, buf_size, &a);            
+    if (a == -1 && lif->token->type != SKIN_TOKEN_VOLUME)
+        a = (out_text && *out_text) ? 1 : 0;
+    switch (lif->operand.type)
+    {
+        case STRING:
+            if (lif->op == IF_EQUALS)
+                return strcmp(out_text, lif->operand.data.text) == 0 ?
+                                                            "eq" : NULL;
+            else
+                return NULL;
+            break;
+        case INTEGER:
+        case DECIMAL:
+            b = lif->operand.data.number;
+            break;
+        case CODE:
+        {
+            char temp_buf[MAX_PATH];
+            const char *outb;
+            struct wps_token *token = lif->operand.data.code->data;
+            b = lif->num_options;
+            outb = get_token_value(gwps, token, offset, temp_buf,
+                                   sizeof(temp_buf), &b);            
+            if (b == -1 && lif->token->type != SKIN_TOKEN_VOLUME)
+            {
+                if (!out_text || !outb)
+                    return (lif->op == IF_EQUALS) ? NULL : "neq";
+                bool equal = strcmp(out_text, outb) == 0;
+                if (lif->op == IF_EQUALS)
+                    return equal ? "eq" : NULL;
+                else if (lif->op == IF_NOTEQUALS)
+                    return !equal ? "neq" : NULL;
+                else
+                    b = (outb && *outb) ? 1 : 0;
+            }
+        }
+        break;
+        case DEFAULT:
+            break;
+    }
+            
+    switch (lif->op)
+    {
+        case IF_EQUALS:
+            return a == b ? "eq" : NULL;
+        case IF_NOTEQUALS:
+            return a != b ? "neq" : NULL;
+        case IF_LESSTHAN:
+            return a < b ? "lt" : NULL;
+        case IF_LESSTHAN_EQ:
+            return a <= b ? "lte" : NULL;
+        case IF_GREATERTHAN:
+            return a > b ? "gt" : NULL;
+        case IF_GREATERTHAN_EQ:
+            return a >= b ? "gte" : NULL;
+    }
+    return NULL;
+}
+
 /* Return the tags value as text. buf should be used as temp storage if needed.
 
    intval is used with conditionals/enums: when this function is called,
@@ -626,66 +693,7 @@ const char *get_token_value(struct gui_wps *gwps,
         case SKIN_TOKEN_LOGICAL_IF:
         {
             struct logical_if *lif = token->value.data;
-            int a = lif->num_options;
-            int b;
-            out_text = get_token_value(gwps, lif->token, offset, buf, buf_size, &a);            
-            if (a == -1 && lif->token->type != SKIN_TOKEN_VOLUME)
-                a = (out_text && *out_text) ? 1 : 0;
-            switch (lif->operand.type)
-            {
-                case STRING:
-                    if (lif->op == IF_EQUALS)
-                        return strcmp(out_text, lif->operand.data.text) == 0 ?
-                                                                    "eq" : NULL;
-                    else
-                        return NULL;
-                    break;
-                case INTEGER:
-                case DECIMAL:
-                    b = lif->operand.data.number;
-                    break;
-                case CODE:
-                {
-                    char temp_buf[MAX_PATH];
-                    const char *outb;
-                    struct wps_token *token = lif->operand.data.code->data;
-                    b = lif->num_options;
-                    outb = get_token_value(gwps, token, offset, temp_buf,
-                                           sizeof(temp_buf), &b);            
-                    if (b == -1 && lif->token->type != SKIN_TOKEN_VOLUME)
-                    {
-                        if (!out_text || !outb)
-                            return (lif->op == IF_EQUALS) ? NULL : "neq";
-                        bool equal = strcmp(out_text, outb) == 0;
-                        if (lif->op == IF_EQUALS)
-                            return equal ? "eq" : NULL;
-                        else if (lif->op == IF_NOTEQUALS)
-                            return !equal ? "neq" : NULL;
-                        else
-                            b = (outb && *outb) ? 1 : 0;
-                    }
-                }
-                break;
-                case DEFAULT:
-                    break;
-            }
-                    
-            switch (lif->op)
-            {
-                case IF_EQUALS:
-                    return a == b ? "eq" : NULL;
-                case IF_NOTEQUALS:
-                    return a != b ? "neq" : NULL;
-                case IF_LESSTHAN:
-                    return a < b ? "lt" : NULL;
-                case IF_LESSTHAN_EQ:
-                    return a <= b ? "lte" : NULL;
-                case IF_GREATERTHAN:
-                    return a > b ? "gt" : NULL;
-                case IF_GREATERTHAN_EQ:
-                    return a >= b ? "gte" : NULL;
-            }
-            return NULL;
+            return get_lif_token_value(gwps, lif, offset, buf, buf_size);
         }
         break;