es_format: Robustification of es_format_copy to avoid a crash reported by Apple-bugreport.

src/misc/es_format.c

@@ -157,15 +157,16 @@ int es_format_Copy( es_format_t *dst, const es_format_t *src )
 {
     int i;
     memcpy( dst, src, sizeof( es_format_t ) );
-    if( src->psz_language )
-         dst->psz_language = strdup( src->psz_language );
-    if( src->psz_description )
-        dst->psz_description = strdup( src->psz_description );
-    if( src->i_extra > 0 )
+    dst->psz_language = src->psz_language ? strdup( src->psz_language ) : NULL;
+    dst->psz_description = src->psz_description ? strdup( src->psz_description ) : NULL;
+    if( src->i_extra > 0 && dst->p_extra )
     {
         dst->i_extra = src->i_extra;
         dst->p_extra = malloc( src->i_extra );
-        memcpy( dst->p_extra, src->p_extra, src->i_extra );
+        if(dst->p_extra)
+            memcpy( dst->p_extra, src->p_extra, src->i_extra );
+        else
+            dst->i_extra = 0;
     }
     else
     {
@@ -173,31 +174,42 @@ int es_format_Copy( es_format_t *dst, const es_format_t *src )
         dst->p_extra = NULL;
     }
 
-    if( src->subs.psz_encoding )
-        dst->subs.psz_encoding = strdup( src->subs.psz_encoding );
+    dst->subs.psz_encoding = dst->subs.psz_encoding ? strdup( src->subs.psz_encoding ) : NULL;
 
     if( src->video.p_palette )
     {
         dst->video.p_palette =
             (video_palette_t*)malloc( sizeof( video_palette_t ) );
-        memcpy( dst->video.p_palette, src->video.p_palette,
+        if(dst->video.p_palette)
+        {
+            memcpy( dst->video.p_palette, src->video.p_palette,
                 sizeof( video_palette_t ) );
+        }
     }
 
-    dst->i_extra_languages = src->i_extra_languages;
-    if( dst->i_extra_languages )
+    if( dst->i_extra_languages && src->p_extra_languages)
+    {
+        dst->i_extra_languages = src->i_extra_languages;
         dst->p_extra_languages = (extra_languages_t*)
             malloc(dst->i_extra_languages * sizeof(*dst->p_extra_languages ));
-    for( i = 0; i < dst->i_extra_languages; i++ ) {
-        if( src->p_extra_languages[i].psz_language )
-            dst->p_extra_languages[i].psz_language = strdup( src->p_extra_languages[i].psz_language );
-        else
-            dst->p_extra_languages[i].psz_language = NULL;
-        if( src->p_extra_languages[i].psz_description )
-            dst->p_extra_languages[i].psz_description = strdup( src->p_extra_languages[i].psz_description );
+        if( dst->p_extra_languages )
+        {
+            for( i = 0; i < dst->i_extra_languages; i++ ) {
+                if( src->p_extra_languages[i].psz_language )
+                    dst->p_extra_languages[i].psz_language = strdup( src->p_extra_languages[i].psz_language );
+                else
+                    dst->p_extra_languages[i].psz_language = NULL;
+                if( src->p_extra_languages[i].psz_description )
+                    dst->p_extra_languages[i].psz_description = strdup( src->p_extra_languages[i].psz_description );
+                else
+                    dst->p_extra_languages[i].psz_description = NULL;
+            }
+        }
         else
-            dst->p_extra_languages[i].psz_description = NULL;
+            dst->i_extra_languages = 0;
     }
+    else
+        dst->i_extra_languages = 0;
     return VLC_SUCCESS;
 }