8230827: javac gives inappropriate warning about potentially ambiguous methods

Fix of too strict com.sun.tools.javac.comp.Comp:checkPotentiallyAmbiguousOverloads method

Reviewed-by: jlahoda

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java

@@ -2686,7 +2686,7 @@ public class Check {
                             types.findDescriptorType(t).getParameterTypes().length()) {
                         potentiallyAmbiguous = true;
                     } else {
-                        break;
+                        return;
                     }
                 }
                 args1 = args1.tail;

test/langtools/tools/javac/8230827/T8230827.java

@@ -0,0 +1,45 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8230827
+ * @summary javac gives inappropriate warning about potentially ambiguous methods
+ * @compile/fail/ref=T8230827.out -XDrawDiagnostics -Xlint:all -Werror T8230827.java
+ */
+
+class T8230827 {
+    interface I1 {
+        void m1(int i);
+    }
+
+    interface I2 {
+        void m2(boolean b);
+    }
+
+    public void nonambiguousMethod1(Boolean differentParam, I1 ambiguousInterface) {}
+
+    public void nonambiguousMethod1(String differentParam, I2 ambiguousInterface) {}
+
+
+    public void nonambiguousMethod2(Object ambiguousParam, I1 ambiguousInterface, String differentParam) {}
+
+    public void nonambiguousMethod2(Object ambiguousParam, I2 ambiguousInterface, Boolean differentParam) {}
+
+
+    public void ambiguousMethod1(Object ambiguousParam, I1 ambiguousInterface) {}
+
+    public void ambiguousMethod1(Object ambiguousParam, I2 ambiguousInterface) {}
+
+
+    public void ambiguousMethod2(I1 ambiguousInterface, Object ambiguousParam) {}
+
+    public void ambiguousMethod2(I2 ambiguousInterface, Object ambiguousParam) {}
+
+
+    public void ambiguousMethod3(I1 ambiguousInterface, I1 sameInterface) {}
+
+    public void ambiguousMethod3(I2 ambiguousInterface, I1 sameInterface) {}
+
+
+    public void ambiguousMethod4(Object ambiguousParent, I1 ambiguousInterface, String ambiguousChild) {}
+
+    public void ambiguousMethod4(String ambiguousChild, I2 ambiguousInterface, Object ambiguousParent) {}
+}

test/langtools/tools/javac/8230827/T8230827.out

@@ -0,0 +1,7 @@
+T8230827.java:27:17: compiler.warn.potentially.ambiguous.overload: ambiguousMethod1(java.lang.Object,T8230827.I1), T8230827, ambiguousMethod1(java.lang.Object,T8230827.I2), T8230827
+T8230827.java:32:17: compiler.warn.potentially.ambiguous.overload: ambiguousMethod2(T8230827.I1,java.lang.Object), T8230827, ambiguousMethod2(T8230827.I2,java.lang.Object), T8230827
+T8230827.java:37:17: compiler.warn.potentially.ambiguous.overload: ambiguousMethod3(T8230827.I1,T8230827.I1), T8230827, ambiguousMethod3(T8230827.I2,T8230827.I1), T8230827
+T8230827.java:42:17: compiler.warn.potentially.ambiguous.overload: ambiguousMethod4(java.lang.Object,T8230827.I1,java.lang.String), T8230827, ambiguousMethod4(java.lang.String,T8230827.I2,java.lang.Object), T8230827
+- compiler.err.warnings.and.werror
+1 error
+4 warnings