# HG changeset patch
# User mcimadamore
# Date 1458752342 0
# Node ID 4e98efed865f5acf0f386ef4135048d0137d8624
# Parent  ae6fa9280e0bfa5dd51b8ad1851cbc1c2702e7ee
8152411: Regression: inference fails to reject incompatible upper bounds
Summary: Wrong undet variable comparison in propagation optimization
Reviewed-by: vromero

diff -r ae6fa9280e0b -r 4e98efed865f langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/InferenceContext.java
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/InferenceContext.java	Wed Mar 23 13:40:42 2016 +0100
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/InferenceContext.java	Wed Mar 23 16:59:02 2016 +0000
@@ -356,6 +356,7 @@
         ListBuffer<Type> minUndetVars = new ListBuffer<>();
         for (Type minVar : minVars) {
             UndetVar uv = (UndetVar)asUndetVar(minVar);
+            Assert.check(uv.incorporationActions.size() == 0);
             UndetVar uv2 = new UndetVar((TypeVar)minVar, infer.incorporationEngine(), types);
             for (InferenceBound ib : InferenceBound.values()) {
                 List<Type> newBounds = uv.getBounds(ib).stream()
@@ -403,15 +404,17 @@
         public Void visitUndetVar(UndetVar t, Void _unused) {
             if (min.add(t.qtype)) {
                 Set<Type> deps = minMap.getOrDefault(t.qtype, new HashSet<>(Collections.singleton(t.qtype)));
-                for (Type b : t.getBounds(InferenceBound.values())) {
-                    Type undet = asUndetVar(b);
-                    if (!undet.hasTag(TypeTag.UNDETVAR)) {
-                        visit(undet);
-                    } else if (isEquiv((UndetVar)undet, b)){
-                        deps.add(b);
-                        equiv.add(b);
-                    } else {
-                        visit(undet);
+                for (InferenceBound boundKind : InferenceBound.values()) {
+                    for (Type b : t.getBounds(boundKind)) {
+                        Type undet = asUndetVar(b);
+                        if (!undet.hasTag(TypeTag.UNDETVAR)) {
+                            visit(undet);
+                        } else if (isEquiv(t, b, boundKind)) {
+                            deps.add(b);
+                            equiv.add(b);
+                        } else {
+                            visit(undet);
+                        }
                     }
                 }
                 minMap.put(t.qtype, deps);
@@ -447,11 +450,17 @@
             return null;
         }
 
-        boolean isEquiv(UndetVar from, Type t) {
+        boolean isEquiv(UndetVar from, Type t, InferenceBound boundKind) {
             UndetVar uv = (UndetVar)asUndetVar(t);
             for (InferenceBound ib : InferenceBound.values()) {
-                List<Type> b1 = uv.getBounds(ib);
-                List<Type> b2 = from.getBounds(ib);
+                List<Type> b1 = from.getBounds(ib);
+                if (ib == boundKind) {
+                    b1 = b1.diff(List.of(t));
+                }
+                List<Type> b2 = uv.getBounds(ib);
+                if (ib == boundKind.complement()) {
+                    b2 = b2.diff(List.of(from.qtype));
+                }
                 if (!b1.containsAll(b2) || !b2.containsAll(b1)) {
                     return false;
                 }
diff -r ae6fa9280e0b -r 4e98efed865f langtools/test/tools/javac/generics/inference/8152411/T8152411.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/8152411/T8152411.java	Wed Mar 23 16:59:02 2016 +0000
@@ -0,0 +1,18 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8152411
+ * @summary Regression: nested unchecked call does not trigger erasure of return type
+ *
+ * @compile/fail/ref=T8152411.out -XDrawDiagnostics T8152411.java
+ */
+import java.util.List;
+
+class T8152411 {
+        <A2 extends A, A> A m(List<? super A2> a2) { return null; }
+        <B> B g(B b) { return null; }
+
+        void test() {
+                List<Integer> I = null;
+                String s = g(m(I));
+        }
+}
diff -r ae6fa9280e0b -r 4e98efed865f langtools/test/tools/javac/generics/inference/8152411/T8152411.out
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/8152411/T8152411.out	Wed Mar 23 16:59:02 2016 +0000
@@ -0,0 +1,2 @@
+T8152411.java:16:29: compiler.err.prob.found.req: (compiler.misc.incompatible.upper.bounds: A2, java.lang.String,B,java.lang.Object,java.lang.Integer,A)
+1 error