8160664: JVM crashed with font manager on Solaris 12

Reviewed-by: prr, aivanov
Contributed-by: NMartin Walsh <martin.walsh@oracle.com>

src/solaris/native/sun/awt/fontpath.c

 /*
- * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -804,6 +804,10 @@ static char **getFontConfigLocations() {
     pattern = (*FcPatternBuild)(NULL, FC_OUTLINE, FcTypeBool, FcTrue, NULL);
     objset = (*FcObjectSetBuild)(FC_FILE, NULL);
     fontSet = (*FcFontList)(NULL, pattern, objset);
+    if (fontSet == NULL) {
+        /* FcFontList() may return NULL if fonts are not installed. */
+        fontdirs = NULL;
+    } else {
         fontdirs = (char**)calloc(fontSet->nfont+1, sizeof(char*));
         for (f=0; f < fontSet->nfont; f++) {
             FcChar8 *file;
@@ -825,9 +829,11 @@ static char **getFontConfigLocations() {
                 }
             }
         }
+        /* Free fontset if one was returned */
+        (*FcFontSetDestroy)(fontSet);
+    }
 
     /* Free memory and close the ".so" */
-    (*FcFontSetDestroy)(fontSet);
     (*FcPatternDestroy)(pattern);
     closeFontConfig(libfontconfig, JNI_TRUE);
     return fontdirs;