don't show run "Class not found" run configuration validation errors in dumb mode (IDEA-194201)

java/execution/openapi/src/com/intellij/execution/configurations/JavaRunConfigurationModule.java

@@ -81,7 +81,12 @@ public class JavaRunConfigurationModule extends RunConfigurationModule {
     final PsiClass psiClass = findClass(className);
     if (psiClass == null) {
       throw new RuntimeConfigurationWarning(
-        ExecutionBundle.message("class.not.found.in.module.error.message", className, getModuleName()));
+        ExecutionBundle.message("class.not.found.in.module.error.message", className, getModuleName())) {
+        @Override
+        public boolean shouldShowInDumbMode() {
+          return false;
+        }
+      };
     }
     return psiClass;
   }

platform/lang-impl/src/com/intellij/execution/impl/SingleConfigurationConfigurable.java

@@ -26,6 +26,7 @@ import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.options.ConfigurationException;
 import com.intellij.openapi.options.SettingsEditor;
 import com.intellij.openapi.options.SettingsEditorListener;
+import com.intellij.openapi.project.DumbService;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.ui.DocumentAdapter;
 import com.intellij.ui.components.JBCheckBox;
@@ -202,6 +203,8 @@ public final class SingleConfigurationConfigurable<Config extends RunConfigurati
   }
 
   private ValidationResult createValidationResult(RunnerAndConfigurationSettings snapshot, ConfigurationException e) {
+    if (!e.shouldShowInDumbMode() && DumbService.isDumb(getConfiguration().getProject())) return null;
+
     return new ValidationResult(
       e.getLocalizedMessage(),
       e instanceof RuntimeConfigurationException ? e.getTitle() : ExecutionBundle.message("invalid.data.dialog.title"),

platform/platform-api/src/com/intellij/openapi/options/ConfigurationException.java

@@ -68,4 +68,12 @@ public class ConfigurationException extends Exception {
   public void setOriginator(Configurable originator) {
     myOriginator = originator;
   }
+
+  /**
+   * @return whether this error should be shown when index isn't complete. Override and return false for errors that
+   * might be caused by inability to find some PSI due to index absence.
+   */
+  public boolean shouldShowInDumbMode() {
+    return true;
+  }
 }