Coverity: Forward NULL: CID 54, 53, 52

[sxemacs] / src / ui / X11 / xgccache.c

diff --git a/src/ui/X11/xgccache.c b/src/ui/X11/xgccache.c
index 9f350c2..068ce4b 100644 (file)
--- a/src/ui/X11/xgccache.c
+++ b/src/ui/X11/xgccache.c
@@ -151,9 +151,11 @@ GC gc_cache_lookup(struct gc_cache *cache, XGCValues * gcv, unsigned long mask)
        struct gc_cache_cell *cell = NULL, *next = NULL, *prev = NULL;
        struct gcv_and_mask gcvm;
 
-       if ((!!cache->head) != (!!cache->tail))
+       if (cache == NULL) 
                abort();
-       else if (cache->head && (cache->head->prev || cache->tail->next))
+       else if ((!!cache->head) != (!!cache->tail))
+               abort();
+       else if (cache->head && cache->tail && (cache->head->prev || cache->tail->next))
                abort();
        else {
                gcvm.mask = mask;
@@ -176,11 +178,9 @@ GC gc_cache_lookup(struct gc_cache *cache, XGCValues * gcv, unsigned long mask)
 
                /* #### This whole file needs some serious overhauling. */
                if (!(mask | GCTile) && cell->gc->values.tile)
-                       cell = 0;
+                       cell = NULL;
                else if (!(mask | GCStipple) && cell->gc->values.stipple)
-                       cell = 0;
-               
-               if (cell)
+                       cell = NULL;
 #endif                         /* !GCCACHE_HASH */
 
                {
@@ -189,38 +189,44 @@ GC gc_cache_lookup(struct gc_cache *cache, XGCValues * gcv, unsigned long mask)
                           be collected than a cell that was accessed
                           less recently.
                        */
-                       if (cell && cell == cache->tail)
-                               return cell->gc;
                        
-                       next = cell->next;
-                       prev = cell->prev;
-                       if (prev)
-                               prev->next = next;
-                       if (next)
-                               next->prev = prev;
-                       if (cache->head == cell)
-                               cache->head = next;
-                       cell->next = 0;
-                       cell->prev = cache->tail;
-                       cache->tail->next = cell;
-                       cache->tail = cell;
-                       if (cache->head == cell)
-                               abort();
-                       else if (cell->next)
+                       if (!cell) {
                                abort();
-                       else if (cache->head->prev)
-                               abort();
-                       else if (cache->tail->next)
-                               abort();
-                       if (cell)
-                               return cell->gc;
-                       else
                                return NULL;
+                       } else {
+                               if (cell == cache->tail)
+                                       return cell->gc;
+                               next = cell->next;
+                               prev = cell->prev;
+                               if (prev)
+                                       prev->next = next;
+                               if (next)
+                                       next->prev = prev;
+                               if (cache->head == cell)
+                                       cache->head = next;
+                               cell->next = NULL;
+                               cell->prev = cache->tail;
+                               if (cache->tail)
+                                       cache->tail->next = cell;
+                               else
+                                       abort();
+                               cache->tail = cell;
+                               if (cache->head == cell)
+                                       abort();
+                               else if (cell->next)
+                                       abort();
+                               else if (cache->head != NULL && cache->head->prev)
+                                       abort();
+                               else if (cache->tail != NULL && cache->tail->next)
+                                       abort();
+                               return cell->gc;
+                       }
                }
                
                /* else, cache miss. */
-               
-               if (cache->size == GC_CACHE_SIZE)
+               if (cache == NULL)
+                       abort();
+               else if (cache->size == GC_CACHE_SIZE)
                        /* Reuse the first cell on the list
                           (least-recently-used).  Remove it from the
                           list, and unhash it from the table.