IDEA-65747 Javadoc: Don't use attribute value on javadoc tag autocompletion

1. Tag name only is used during javadoc tag auto completion;
2. Corresponding test is added;
3. java-impl module config file is corrected in order to define test source root;

java/java-impl/java-impl.iml

@@ -4,6 +4,7 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/testSrc" isTestSource="true" />
     </content>
     <orderEntry type="module" module-name="boot" />
     <orderEntry type="inheritedJdk" />

java/java-impl/src/com/intellij/codeInsight/editorActions/JavadocTypedHandler.java

@@ -117,6 +117,11 @@ public class JavadocTypedHandler extends TypedHandlerDelegate {
             return null;
           }
           return text.subSequence(i + 1, endOffset).toString();
+        
+        // There is a possible case that opening tag has attributes, e.g. <a href='bla-bla-bla'>[offset]. We want to extract
+        // only tag name then.
+        case ' ':
+        case '\t': endOffset = i;
       }
     }
     return null;

java/java-impl/testSrc/com/intellij/codeInsight/editorActions/JavadocTypedHandlerTest.java

@@ -37,6 +37,12 @@ public class JavadocTypedHandlerTest {
     doTest("<t\nag><caret>", null);
   }
   
+  @Test
+  public void tagWithAttribute() {
+    doTest("<a href='www'><caret>", "a");
+    //TODO den implement
+  }
+  
   private static void doTest(String text, String expected) {
     StringBuilder normalized = new StringBuilder();
     int offset = text.indexOf(CARET_MARKER);