--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Fri Mar 24 12:33:29 2017 +0000
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Fri Mar 24 13:04:32 2017 +0000
@@ -448,13 +448,21 @@
 
         NORMAL,
 
-        NO_TREE_UPDATE {     // Mode signalling 'fake check' - skip tree update
+        /**
+         * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
+         * that the captured var cache in {@code InferenceContext} will be used in read-only
+         * mode when performing inference checks.
+         */
+        NO_TREE_UPDATE {
             @Override
             public boolean updateTreeType() {
                 return false;
             }
         },
-        NO_INFERENCE_HOOK { // Mode signalling that caller will manage free types in tree decorations.
+        /**
+         * Mode signalling that caller will manage free types in tree decorations.
+         */
+        NO_INFERENCE_HOOK {
             @Override
             public boolean installPostInferenceHook() {
                 return false;
@@ -3769,7 +3777,7 @@
                 break;
             case MTH: {
                 owntype = checkMethod(site, sym,
-                        new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext),
+                        new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
                         resultInfo.pt.getTypeArguments());
                 break;

--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java	Fri Mar 24 12:33:29 2017 +0000
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java	Fri Mar 24 13:04:32 2017 +0000
@@ -27,6 +27,7 @@
 
 import com.sun.tools.javac.code.Type.UndetVar.UndetVarListener;
 import com.sun.tools.javac.code.Types.TypeMapping;
+import com.sun.tools.javac.comp.Attr.CheckMode;
 import com.sun.tools.javac.tree.JCTree;
 import com.sun.tools.javac.tree.JCTree.JCTypeCast;
 import com.sun.tools.javac.tree.TreeInfo;
@@ -419,7 +420,7 @@
             }
         } else if (rsInfoInfContext.free(resultInfo.pt)) {
             //propagation - cache captured vars
-            qtype = inferenceContext.asUndetVar(rsInfoInfContext.cachedCapture(tree, from, false));
+            qtype = inferenceContext.asUndetVar(rsInfoInfContext.cachedCapture(tree, from, !resultInfo.checkMode.updateTreeType()));
         }
         Assert.check(allowGraphInference || !rsInfoInfContext.free(to),
                 "legacy inference engine cannot handle constraints on both sides of a subtyping assertion");
@@ -509,7 +510,7 @@
         inferenceContext.solve(List.of(from.qtype), new Warner());
         inferenceContext.notifyChange();
         Type capturedType = resultInfo.checkContext.inferenceContext()
-                .cachedCapture(tree, from.getInst(), false);
+                .cachedCapture(tree, from.getInst(), !resultInfo.checkMode.updateTreeType());
         if (types.isConvertible(capturedType,
                 resultInfo.checkContext.inferenceContext().asUndetVar(to))) {
             //effectively skip additional return-type constraint generation (compatibility)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/8177097/T8177097a.java	Fri Mar 24 13:04:32 2017 +0000
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8177097
+ * @summary Generic method reference returning wildcard parameterized type does not compile
+ * @compile T8177097a.java
+ */
+
+import java.util.Map;
+
+class T8177097a {
+    interface X<O> {
+        Map<?, O> apply();
+    }
+
+    <O> void go(X<O> x) { }
+
+    static <I> Map<?, Integer> a() {
+        return null;
+    }
+
+    void test() {
+        go(T8177097a::a);
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/8177097/T8177097b.java	Fri Mar 24 13:04:32 2017 +0000
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8177097
+ * @summary Generic method reference returning wildcard parameterized type does not compile
+ * @compile T8177097b.java
+ */
+
+import java.util.Map;
+
+class T8177097b {
+    interface X<O> {
+        O apply(Class<Map<Integer, ?>> m2);
+    }
+
+    <O> void go(X<O> x) {}
+
+    static <I> I a(Class<I> c) { return null; }
+
+
+    void test() {
+        go(T8177097b::a);
+    }
+}