when paused use EDT thread as current

java/debugger/impl/src/com/intellij/debugger/impl/DebuggerSession.java

@@ -36,6 +36,7 @@ import com.intellij.psi.PsiCompiledElement;
 import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.unscramble.ThreadState;
 import com.intellij.xdebugger.AbstractDebuggerSession;
 import com.sun.jdi.ObjectCollectedException;
 import com.sun.jdi.ThreadReference;
@@ -44,6 +45,7 @@ import com.sun.jdi.request.EventRequest;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -367,12 +369,23 @@ public class DebuggerSession implements AbstractDebuggerSession {
         }
 
         if(currentThread == null) {
-          for (final ThreadReferenceProxyImpl threadReferenceProxy : getProcess().getVirtualMachineProxy().allThreads()) {
-            currentThread = threadReferenceProxy;
-            if (currentThread.status() == ThreadReference.THREAD_STATUS_RUNNING) {
+          final Collection<ThreadReferenceProxyImpl> allThreads = getProcess().getVirtualMachineProxy().allThreads();
+          // heuristics: try to pre-select EventDispatchThread
+          for (final ThreadReferenceProxyImpl thread : allThreads) {
+            if (ThreadState.isEDT(thread.name())) {
+              currentThread = thread;
               break;
             }
           }
+          if (currentThread == null) {
+            // heuristics: display the first thread with RUNNABLE status
+            for (final ThreadReferenceProxyImpl thread : allThreads) {
+              currentThread = thread;
+              if (currentThread.status() == ThreadReference.THREAD_STATUS_RUNNING) {
+                break;
+              }
+            }
+          }
         }
 
         StackFrameProxyImpl proxy = null;

java/java-impl/src/com/intellij/unscramble/ThreadState.java

@@ -128,6 +128,11 @@ public class ThreadState {
   }
 
   public boolean isEDT() {
-    return getName().startsWith("AWT-EventQueue");
+    final String name = getName();
+    return isEDT(name);
+  }
+
+  public static boolean isEDT(String name) {
+    return name.startsWith("AWT-EventQueue");
   }
 }