Fix for FS#1334, see also FS#1090

FS#1090 ensured DW would never rebuild instructions in the same run by forcing subsequent
instruction requests to use the version cached on the first request.  That introduced problems
when the caching of the instructions failed (FS#1334).  This patch allows subsequent rebuilds
when cache storage failed.

darcs-hash:20080223025539-d26fc-26202a049a6969816553d950a2bb8f71a02ae76e.gz

inc/cache.php

@@ -105,10 +105,10 @@ class cache {
    * cache $data
    *
    * @param   string $data   the data to be cached
-   * @return  none
+   * @return  bool           true on success, false otherwise
    */
   function storeCache($data) {
-    io_savefile($this->cache, $data);
+    return io_savefile($this->cache, $data);
   }
 
   /**
@@ -286,6 +286,6 @@ class cache_instructions extends cache_parser {
   }
 
   function storeCache($instructions) {
-    io_savefile($this->cache,serialize($instructions));
+    return io_savefile($this->cache,serialize($instructions));
   }
 }

inc/parserutils.php

@@ -183,8 +183,11 @@ function p_cached_instructions($file,$cacheonly=false,$id='') {
   } else if (@file_exists($file)) {
     // no cache - do some work
     $ins = p_get_instructions(io_readfile($file));
-    $cache->storeCache($ins);
-    $run[$file] = true; // we won't rebuild these instructions in the same run again
+    if ($cache->storeCache($ins)) {
+      $run[$file] = true; // we won't rebuild these instructions in the same run again
+    } else {
+      msg('Unable to save cache file. Hint: disk full; file permissions; safe_mode setting.',-1);
+    }
     return $ins;
   }