show run menu: make cache null friendly (IDEA-149102)

platform/lang-api/src/com/intellij/execution/actions/ConfigurationContext.java

@@ -58,6 +58,7 @@ public class ConfigurationContext {
   private static final Logger LOG = Logger.getInstance("#com.intellij.execution.actions.ConfigurationContext");
   private final Location<PsiElement> myLocation;
   private RunnerAndConfigurationSettings myConfiguration;
+  private boolean myInitialized = false;
   private Ref<RunnerAndConfigurationSettings> myExistingConfiguration;
   private final Module myModule;
   private final RunConfiguration myRuntimeConfiguration;
@@ -118,8 +119,10 @@ public class ConfigurationContext {
    * @return the configuration, or null if none of the producers were able to create a configuration from this context.
    */
   @Nullable
-  public RunnerAndConfigurationSettings getConfiguration() {
-    if (myConfiguration == null) createConfiguration();
+  public synchronized RunnerAndConfigurationSettings getConfiguration() {
+    if (myConfiguration == null && !myInitialized) {
+      createConfiguration();
+    }
     return myConfiguration;
   }
 
@@ -129,10 +132,12 @@ public class ConfigurationContext {
     myConfiguration = location != null && !DumbService.isDumb(location.getProject()) ?
         PreferredProducerFind.createConfiguration(location, this) :
         null;
+    myInitialized = true;
   }
 
-  public void setConfiguration(RunnerAndConfigurationSettings configuration) {
+  public synchronized void setConfiguration(@NotNull RunnerAndConfigurationSettings configuration) {
     myConfiguration = configuration;
+    myInitialized = true;
   }
 
   @Deprecated