From 49af1907b82be03ee4848b415564bc1f1e26e6bd Mon Sep 17 00:00:00 2001
From: William S Fulton <wsf@fultondesigns.co.uk>
Date: Fri, 12 Jan 2018 07:34:32 +0000
Subject: [PATCH] Add missing Java throws clause for interfaces when using the
 %interface family of macros.

Fixes #1156.
---
 CHANGES.current                               |  4 ++++
 .../test-suite/java/java_throws_runme.java    | 22 +++++++++++++++++++
 Examples/test-suite/java_throws.i             | 17 ++++++++++++++
 Source/Modules/java.cxx                       |  7 ++++--
 4 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/CHANGES.current b/CHANGES.current
index f39960bc3..0aad216de 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,10 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.0.0 (in progress)
 ===========================
 
+2018-01-12: wsfulton
+            [Java] Fix issue #1156. Add missing throws clause for interfaces when using the
+            %interface family of macros.
+
 2018-01-05: wsfulton
             Fix default arguments using expressions containing -> syntax error. Problem reported on
             swig-user mailing list.
diff --git a/Examples/test-suite/java/java_throws_runme.java b/Examples/test-suite/java/java_throws_runme.java
index 0365b69ed..16eab7cad 100644
--- a/Examples/test-suite/java/java_throws_runme.java
+++ b/Examples/test-suite/java/java_throws_runme.java
@@ -93,6 +93,28 @@ public class java_throws_runme {
       if (!pass)
         throw new RuntimeException("Test 6 failed");
 
+      // Interface function
+      pass = false;
+      try {
+        InterfaceTestImpl iti = new InterfaceTestImpl();
+        iti.imethod(true);
+      }
+      catch (MyException e) { pass = true; }
+
+      if (!pass)
+        throw new RuntimeException("Test interface 1 failed");
+
+      pass = false;
+      try {
+        InterfaceTestImpl iti = new InterfaceTestImpl();
+        iti.imethod(false);
+        pass = true;
+      }
+      catch (MyException e) { pass = false; }
+
+      if (!pass)
+        throw new RuntimeException("Test interface 2 failed");
+
       // Global function
       pass = false;
       try {
diff --git a/Examples/test-suite/java_throws.i b/Examples/test-suite/java_throws.i
index c628a45e6..875bce0ff 100644
--- a/Examples/test-suite/java_throws.i
+++ b/Examples/test-suite/java_throws.i
@@ -135,6 +135,23 @@ JAVAEXCEPTION(FeatureTest::staticMethod)
     };
 %}
 
+%include <swiginterface.i>
+%interface_impl(InterfaceTest);
+JAVAEXCEPTION(imethod)
+
+%inline %{
+    struct InterfaceTest {
+        virtual void imethod(bool raise) = 0;
+    };
+
+    struct InterfaceTestImpl : InterfaceTest {
+        void imethod(bool raise) {
+            if (raise)
+                throw MyException("raise message");
+        }
+    };
+%}
+
 // Mixing except feature and typemaps when both generate a class for the throws clause
 %typemap(in, throws="ClassNotFoundException") int both { 
     $1 = (int)$input;
diff --git a/Source/Modules/java.cxx b/Source/Modules/java.cxx
index f759aaf5d..d2b25426a 100644
--- a/Source/Modules/java.cxx
+++ b/Source/Modules/java.cxx
@@ -2544,8 +2544,6 @@ public:
 
     Printf(imcall, ")");
     Printf(function_code, ")");
-    if (is_interface)
-      Printf(interface_class_code, ");\n");
 
     // Transform return type used in JNI function (in intermediary class) to type used in Java wrapper function (in proxy class)
     if ((tm = Swig_typemap_lookup("javaout", n, "", 0))) {
@@ -2603,6 +2601,11 @@ public:
       Swig_warning(WARN_JAVA_TYPEMAP_JAVAOUT_UNDEF, input_file, line_number, "No javaout typemap defined for %s\n", SwigType_str(t, 0));
     }
 
+    if (is_interface) {
+      Printf(interface_class_code, ")");
+      generateThrowsClause(n, interface_class_code);
+      Printf(interface_class_code, ";\n");
+    }
     generateThrowsClause(n, function_code);
     Printf(function_code, " %s\n\n", tm ? (const String *) tm : empty_string);
     Printv(proxy_class_code, function_code, NIL);