From 21a5df9e7cf66f86b75dd0373a356a3251ad01e7 Mon Sep 17 00:00:00 2001
From: Timothy Wall <twalljava@java.net>
Date: Sun, 6 Dec 2015 10:20:08 -0500
Subject: [PATCH] Add test for small stdcall arguments

---
 native/testlib.c                                 |  5 +++++
 src/com/sun/jna/win32/StdCallFunctionMapper.java | 10 ++++++++--
 test/com/sun/jna/win32/W32StdCallTest.java       |  9 +++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/native/testlib.c b/native/testlib.c
index 7080d1d76d..11f8a2bee5 100644
--- a/native/testlib.c
+++ b/native/testlib.c
@@ -925,6 +925,11 @@ returnStructureByValueArgumentStdCall(TestStructureByValue arg) {
   return arg;
 }
 
+EXPORT int16_t __stdcall
+returnInt16ArgumentStdCall(int16_t arg1, int16_t arg2, void* buffer, int16_t len) {
+  return len;
+}
+
 EXPORT int32_t __stdcall
 callInt32StdCallCallback(int32_t (__stdcall *func)(int32_t arg, int32_t arg2),
                          int32_t arg, int32_t arg2) {
diff --git a/src/com/sun/jna/win32/StdCallFunctionMapper.java b/src/com/sun/jna/win32/StdCallFunctionMapper.java
index 1a78c578fd..5e2913d40e 100644
--- a/src/com/sun/jna/win32/StdCallFunctionMapper.java
+++ b/src/com/sun/jna/win32/StdCallFunctionMapper.java
@@ -40,7 +40,7 @@ protected int getArgumentNativeStackSize(Class cls) {
             return Pointer.SIZE;
         }
         try {
-            return Native.getNativeSize(cls);
+            return Math.max(4, Native.getNativeSize(cls));
         }
         catch(IllegalArgumentException e) {
             throw new IllegalArgumentException("Unknown native stack allocation size for " + cls);
@@ -59,12 +59,18 @@ public String getFunctionName(NativeLibrary library, Method method) {
         String decorated = name + "@" + pop;
         int conv = StdCallLibrary.STDCALL_CONVENTION;
         try {
+            if (Native.DEBUG_LOAD) {
+                System.out.println("Trying " + decorated);
+            }
             name = library.getFunction(decorated, conv).getName();
 
         }
         catch(UnsatisfiedLinkError e) {
             // try with an explicit underscore
             try {
+                if (Native.DEBUG_LOAD) {
+                    System.out.println("Trying _" + decorated);
+                }
                 name = library.getFunction("_" + decorated, conv).getName();
             }
             catch(UnsatisfiedLinkError e2) {
@@ -73,4 +79,4 @@ public String getFunctionName(NativeLibrary library, Method method) {
         }
         return name;
     }
-}
\ No newline at end of file
+}
diff --git a/test/com/sun/jna/win32/W32StdCallTest.java b/test/com/sun/jna/win32/W32StdCallTest.java
index 5404c32a81..5bce3a0ee5 100644
--- a/test/com/sun/jna/win32/W32StdCallTest.java
+++ b/test/com/sun/jna/win32/W32StdCallTest.java
@@ -24,6 +24,7 @@
 import com.sun.jna.Native;
 import com.sun.jna.NativeLibrary;
 import com.sun.jna.NativeLong;
+import com.sun.jna.Pointer;
 import com.sun.jna.Structure;
 
 /**
@@ -50,6 +51,7 @@ protected List getFieldOrder() {
             }
         }
         int returnInt32ArgumentStdCall(int arg);
+        short returnInt16ArgumentStdCall(short arg1, short arg2, Pointer buf, short len);
         TestStructure.ByValue returnStructureByValueArgumentStdCall(TestStructure.ByValue arg);
         interface Int32Callback extends StdCallCallback {
             int callback(int arg, int arg2);
@@ -125,6 +127,13 @@ public void testStdCallReturnStructureByValueArgument() {
         assertTrue("Wrong struct value", s.dataEquals(testlib.returnStructureByValueArgumentStdCall(s)));
     }
     
+    public void testStdCallStackAlignment() {
+        final short MAGIC = 0x1234;
+        assertEquals("Incorrect stdcall stack alignment", MAGIC,
+                     testlib.returnInt16ArgumentStdCall((short)1, (short)2,
+                                                        null, MAGIC));
+    }
+
     public void testStdCallCallback() {
         final int MAGIC = 0x11111111;
         final boolean[] called = { false };