issue #4060 - Key stuck down on Windows server

finished solving issue.

src/lib/platform/MSWindowsKeyState.cpp

@@ -909,7 +909,10 @@ CMSWindowsKeyState::pollPressedKeys(KeyButtonSet& pressedKeys) const
 	}
 	for (KeyButton i = 1; i < 256; ++i) {
 		if ((keyState[i] & 0x80) != 0) {
-			pressedKeys.insert(i);
+			KeyButton keyButton = virtualKeyToButton(i);
+			if (keyButton != 0) {
+				pressedKeys.insert(keyButton);
+			}
 		}
 	}
 }
@@ -1344,6 +1347,12 @@ CMSWindowsKeyState::getKeyID(UINT virtualKey, KeyButton button)
 	return s_virtualKey[virtualKey];
 }
 
+UINT
+CMSWindowsKeyState::mapButtonToVirtualKey(KeyButton button) const
+{
+	return m_buttonToVK[button];
+}
+
 KeyID
 CMSWindowsKeyState::getIDForKey(CKeyMap::KeyItem& item,
 				KeyButton button, UINT virtualKey,

src/lib/platform/MSWindowsKeyState.h

@@ -124,6 +124,14 @@ public:
 	*/
 	static KeyID		getKeyID(UINT virtualKey, KeyButton button);
 
+	//! Map button to virtual key
+	/*!
+	Returns the virtual key for button \p button
+	(button should include the extended key bit), or kKeyNone if there is
+	no such key.
+	*/
+	UINT				mapButtonToVirtualKey(KeyButton button) const;
+
 	//@}
 
 	// IKeyState overrides

src/lib/platform/MSWindowsScreen.cpp

@@ -46,6 +46,7 @@
 #include <pbt.h>
 #include <Shlobj.h>
 #include <comutil.h>
+#include <algorithm>
 
 //
 // add backwards compatible multihead support (and suppress bogus warning).
@@ -302,7 +303,10 @@ CMSWindowsScreen::enter()
 
 		// all messages prior to now are invalid
 		nextMark();
-	} else {
+
+		m_primaryKeyDownList.clear();
+	}
+	else {
 		// Entering a secondary screen. Ensure that no screensaver is active
 		// and that the screen is not in powersave mode.
 		CArchMiscWindows::wakeupDisplay();
@@ -351,6 +355,14 @@ CMSWindowsScreen::leave()
 		m_keyState->saveModifiers();
 
 		m_hook.setMode(kHOOK_RELAY_EVENTS);
+
+		m_primaryKeyDownList.clear();
+		for (KeyButton i = 0; i < IKeyState::kNumButtons; ++i) {
+			if (m_keyState->isKeyDown(i)) {
+				m_primaryKeyDownList.push_back(i);
+				LOG((CLOG_DEBUG1 "key button %d is down before leaving to another screen", i));
+			}
+		}
 	}
 
 	// now off screen
@@ -1137,6 +1149,18 @@ CMSWindowsScreen::onKey(WPARAM wParam, LPARAM lParam)
 	// record keyboard state
 	m_keyState->onKey(button, down, oldState);
 
+	if (!down && m_isPrimary && !m_isOnScreen) {
+		PrimaryKeyDownList::iterator find = std::find(m_primaryKeyDownList.begin(), m_primaryKeyDownList.end(), button);
+		if (find != m_primaryKeyDownList.end()) {
+			LOG((CLOG_DEBUG1 "release key button %d on primary", *find));
+			m_hook.setMode(kHOOK_WATCH_JUMP_ZONE);
+			fakeLocalKey(*find, false);
+			m_primaryKeyDownList.erase(find);
+			m_hook.setMode(kHOOK_RELAY_EVENTS);
+			return true;
+		}
+	}
+
 	// windows doesn't tell us the modifier key state on mouse or key
 	// events so we have to figure it out.  most apps would use
 	// GetKeyState() or even GetAsyncKeyState() for that but we can't
@@ -1802,6 +1826,19 @@ CMSWindowsScreen::wndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 	return result;
 }
 
+void
+CMSWindowsScreen::fakeLocalKey(KeyButton button, bool press) const
+{
+	INPUT input;
+	input.type = INPUT_KEYBOARD;
+	input.ki.wVk =  m_keyState->mapButtonToVirtualKey(button);
+	DWORD pressFlag = press ? KEYEVENTF_EXTENDEDKEY : KEYEVENTF_KEYUP;
+	input.ki.dwFlags = pressFlag;
+	input.ki.time = 0;
+	input.ki.dwExtraInfo = 0;
+	SendInput(1,&input,sizeof(input));
+}
+
 //
 // CMSWindowsScreen::CHotKeyItem
 //

src/lib/platform/MSWindowsScreen.h

@@ -127,6 +127,9 @@ protected:
 	virtual void		updateButtons();
 	virtual IKeyState*	getKeyState() const;
 
+	// simulate a local key to the system directly
+	void				fakeLocalKey(KeyButton button, bool press) const;
+
 private:
 	// initialization and shutdown operations
 	HCURSOR				createBlankCursor() const;
@@ -236,6 +239,7 @@ private:
 	typedef std::map<UInt32, CHotKeyItem> HotKeyMap;
 	typedef std::vector<UInt32> HotKeyIDList;
 	typedef std::map<CHotKeyItem, UInt32> HotKeyToIDMap;
+	typedef std::vector<KeyButton> PrimaryKeyDownList;
 
 	static HINSTANCE	s_windowInstance;
 
@@ -335,4 +339,6 @@ private:
 	const int			m_dropWindowSize;
 
 	CThread*			m_sendDragThread;
+
+	PrimaryKeyDownList	m_primaryKeyDownList;
 };

src/lib/synergy/KeyState.cpp

@@ -903,7 +903,6 @@ CKeyState::updateModifierKeyState(KeyButton button,
 	}
 }
 
-
 //
 // CKeyState::CAddActiveModifierContext
 //