[hotfix] Guard against null python language home

PullRequest: graalpython/413

Author: ansalond

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonCore.java

@@ -130,7 +130,7 @@ public static String getSysBasePrefix(TruffleLanguage.Env env) {
         String sysPrefix = env.getOptions().get(PythonOptions.SysBasePrefix);
         if (sysPrefix.isEmpty()) {
             String homePrefix = PythonLanguage.getCurrent().getHome();
-            if (homePrefix.isEmpty()) {
+            if (homePrefix == null || homePrefix.isEmpty()) {
                 homePrefix = PREFIX;
             }
             env.getOptions().set(PythonOptions.SysBasePrefix, homePrefix);

mx.graalpython/suite.py

@@ -9,7 +9,7 @@
     "name": "graalpython",
     "versionConflictResolution": "latest",
 
-    "version": "1.0.0-rc13",
+    "version": "1.0.0-rc14",
     "release": False,
     "groupId": "org.graalvm.graalpython",
     "url": "http://www.graalvm.org/",