support for constructor functions that return itself
if the constructor function is not called with "new"

plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/validation/FlowValidation.java

diff --git a/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/validation/FlowValidation.java b/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/validation/FlowValidation.java
index 0a14be7..ac2b361 100644
--- a/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/validation/FlowValidation.java
+++ b/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/validation/FlowValidation.java
@@ -18,6 +18,7 @@
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.dltk.core.builder.IBuildContext;
 import org.eclipse.dltk.core.builder.IBuildParticipant;
+import org.eclipse.dltk.internal.javascript.ti.JSDocSupport;
 import org.eclipse.dltk.javascript.ast.AbstractNavigationVisitor;
 import org.eclipse.dltk.javascript.ast.BreakStatement;
 import org.eclipse.dltk.javascript.ast.CaseClause;
@@ -44,6 +45,8 @@
 import org.eclipse.dltk.javascript.ast.WhileStatement;
 import org.eclipse.dltk.javascript.core.JavaScriptProblems;
 import org.eclipse.dltk.javascript.parser.Reporter;
+import org.eclipse.dltk.javascript.parser.jsdoc.JSDocTag;
+import org.eclipse.dltk.javascript.parser.jsdoc.JSDocTags;
 import org.eclipse.osgi.util.NLS;
 
 public class FlowValidation extends AbstractNavigationVisitor<FlowStatus>
@@ -204,6 +207,17 @@
 			final FlowStatus result = super.visitFunctionStatement(node);
 			if (scope.contains(FlowEndKind.RETURNS_VALUE)
 					&& (scope.contains(FlowEndKind.RETURNS) || result.noReturn)) {
+				if (result.noReturn && result.returnValue
+						&& node.getDocumentation() != null) {
+					JSDocTags parse = JSDocSupport.parse(node
+							.getDocumentation());
+					// if it does return a value and it has a no return and it
+					// is a constructor function then don't report it. Very
+					// likely a construct to support a constructor function
+					// without the new keyword.
+					if (parse.count(JSDocTag.CONSTRUCTOR) == 1)
+						return result;
+				}
 				reportInconsistentReturn(node);
 			}
 			return result;

tests/org.eclipse.dltk.javascript.core.tests/src/org/eclipse/dltk/javascript/core/tests/validation/FlowValidationTests.java

diff --git a/tests/org.eclipse.dltk.javascript.core.tests/src/org/eclipse/dltk/javascript/core/tests/validation/FlowValidationTests.java b/tests/org.eclipse.dltk.javascript.core.tests/src/org/eclipse/dltk/javascript/core/tests/validation/FlowValidationTests.java
index f5c66d1..c8bfa1a 100644
--- a/tests/org.eclipse.dltk.javascript.core.tests/src/org/eclipse/dltk/javascript/core/tests/validation/FlowValidationTests.java
+++ b/tests/org.eclipse.dltk.javascript.core.tests/src/org/eclipse/dltk/javascript/core/tests/validation/FlowValidationTests.java
@@ -454,5 +454,30 @@
 		final List<IProblem> problems = validate(sCode);
 		assertEquals(problems.toString(), 0, problems.size());
 	}
+	
+	
+	public void testConstructorFunctionReturningItself() {
+		final StringList code = new StringList();
+		code.add("/**");
+		code.add(" * @constructor");
+		code.add(" */");
+		code.add("function MyConstructor(){");
+		code.add("	if (!(this instanceof MyConstructor))");
+		code.add("	  { return new MyConstructor() }");
+		code.add("}");
+		final String sCode = code.toString();
+		final List<IProblem> problems = validate(sCode);
+		assertEquals(problems.toString(), 0, problems.size());
+	}
 
+	public void testFunctionReturningItself() {
+		final StringList code = new StringList();
+		code.add("function MyConstructor(){");
+		code.add("	if (!(this instanceof MyConstructor))");
+		code.add("	  { return new MyConstructor() }");
+		code.add("}");
+		final String sCode = code.toString();
+		final List<IProblem> problems = validate(sCode);
+		assertEquals(problems.toString(), 1, problems.size());
+	}
 }