From 5488b77d613659843785dbdb3bca2e41f3016ba6 Mon Sep 17 00:00:00 2001
From: crs <cschoeneman@gmail.com>
Date: Sun, 13 Jul 2003 20:42:11 +0000
Subject: [PATCH] Fixed handling of some keystrokes on win32.  Pressing a dead
 key and then space should convert the dead key to a non-dead key but previous
 the key was discarded.  Fixed that but VkKeyScan() fails in this case so
 added special case to fix that (assuming AltGr is required).  VkKeyScan() can
 return the wrong result for characters that have more than one virtual key
 mapped to them.  AltGr+9 (^) on the French layout has this problem.  Now
 detecting that problem and using the current keyboard state to decide if
 AltGr is required.

---
 lib/platform/CMSWindowsPrimaryScreen.cpp | 40 +++++++++++++++++++-----
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/lib/platform/CMSWindowsPrimaryScreen.cpp b/lib/platform/CMSWindowsPrimaryScreen.cpp
index 1eec8050..5871f724 100644
--- a/lib/platform/CMSWindowsPrimaryScreen.cpp
+++ b/lib/platform/CMSWindowsPrimaryScreen.cpp
@@ -1144,7 +1144,7 @@ static const KeyID		g_virtualKey[][2] =
 	/* 0x1d */ kKeyNone,		kKeyNone,		// VK_NONCONVERT	
 	/* 0x1e */ kKeyNone,		kKeyNone,		// VK_ACCEPT		
 	/* 0x1f */ kKeyNone,		kKeyNone,		// VK_MODECHANGE	
-	/* 0x20 */ 0x0020,			kKeyNone,		// VK_SPACE
+	/* 0x20 */ kKeyNone,		kKeyNone,		// VK_SPACE
 	/* 0x21 */ kKeyKP_PageUp,	kKeyPageUp,		// VK_PRIOR
 	/* 0x22 */ kKeyKP_PageDown,	kKeyPageDown,	// VK_NEXT
 	/* 0x23 */ kKeyKP_End,		kKeyEnd,		// VK_END
@@ -1421,7 +1421,8 @@ CMSWindowsPrimaryScreen::mapKey(
 
 		// convert to ascii
 		WORD ascii;
-		int result = ToAscii(vkCode, scanCode, m_keys, &ascii, 0);
+		int result = ToAscii(vkCode, scanCode, m_keys, &ascii,
+								((menu & 0x80) == 0) ? 0 : 1);
 
 		// restore control state
 		m_keys[VK_LCONTROL] = lControl;
@@ -1504,13 +1505,38 @@ CMSWindowsPrimaryScreen::mapKey(
 	// set mask
 	*altgr = false;
 	if (id != kKeyNone && id != kKeyMultiKey && c != 0) {
-		// note if key requires AltGr
-		SHORT virtualKeyAndModifierState = VkKeyScan(c);
-		BYTE modifierState = HIBYTE(virtualKeyAndModifierState);
-		if ((modifierState & 6) == 6) {
-			// key requires ctrl and alt == AltGr
+		// note if key requires AltGr.  VkKeyScan() can have a problem
+		// with some characters.  there are two problems in particular.
+		// first, typing a dead key then pressing space will cause
+		// VkKeyScan() to return 0xffff.  second, certain characters
+		// may map to multiple virtual keys and we might get the wrong
+		// one.  if that happens then we might not get the right
+		// modifier mask.  AltGr+9 on the french keyboard layout (^)
+		// has this problem.  in the first case, we'll assume AltGr is
+		// required (only because it solves the problems we've seen
+		// so far).  in the second, we'll use whatever the keyboard
+		// state says.
+		WORD virtualKeyAndModifierState = VkKeyScan(c);
+		if (virtualKeyAndModifierState == 0xffff) {
+			// there is no mapping.  assume AltGr.
+			LOG((CLOG_DEBUG1 "no VkKeyScan() mapping"));
 			*altgr = true;
 		}
+		else if (LOBYTE(virtualKeyAndModifierState) != vkCode) {
+			// we didn't get the key that was actually pressed
+			LOG((CLOG_DEBUG1 "VkKeyScan() mismatch"));
+			if ((m_keys[VK_CONTROL] & 0x80) != 0 &&
+				(m_keys[VK_MENU] & 0x80) != 0) {
+				*altgr = true;
+			}
+		}
+		else {
+			BYTE modifierState = HIBYTE(virtualKeyAndModifierState);
+			if ((modifierState & 6) == 6) {
+				// key requires ctrl and alt == AltGr
+				*altgr = true;
+			}
+		}
 
 		// map modifier key
 		KeyModifierMask mask = 0;