client: fix for redundant shift+f11 RHBZ #674532

After shift+F11, both in Windows 7 and xp clients, WM_KEYUP events were missing for
SHIFT and F11. For F11 it was less important since unpress_all was preformed for all keys.
However, we perform sync for all the keyboard modifiers and the GetKeyboardState returns "down" for shift.
In windows7 client, we sometimes received afterwards a F11 KEYDOWN event repetition, and this caused SHIFT+F11 to be called again.
Not performing hiding of the windows while changing client resolutions, solved the problem of missing events, and I don't see any difference
in how spice looks while toggling to full screen.
Using GetAsyncKeyState, returns "UP" for shift in windows 7, and helps avoid performing shift+f11 again, if there is an F11 repetition
before we receive the KEYUP event for shift.

3 files changed, 27 insertions, 10 deletions

diff --git a/client/application.cpp b/client/application.cpp
index 606f7e2..8e9fd8a 100644
--- a/client/application.cpp
+++ b/client/application.cpp
@@ -1524,7 +1524,11 @@ void Application::enter_full_screen()
     _changing_screens = true;
     bool capture = release_capture();
     assign_monitors();
+#ifndef WIN32
+    /* performing hide during resolution changes resulted in
+       missing WM_KEYUP events */
     hide();
+#endif
     prepare_monitors();
     position_screens();
     show_full_screen();
diff --git a/client/screen.cpp b/client/screen.cpp
index f17a0ba..7259ed4 100644
--- a/client/screen.cpp
+++ b/client/screen.cpp
@@ -830,7 +830,11 @@ void RedScreen::show_full_screen()
         return;
     }
     RecurciveLock lock(_update_lock);
+#ifndef WIN32
+    /* performing hide during resolution changes resulted in
+       missing WM_KEYUP events */
     hide();
+#endif
     save_position();
     _full_screen = true;
     __show_full_screen();
diff --git a/client/windows/platform.cpp b/client/windows/platform.cpp
index b81c2f5..a99d438 100644
--- a/client/windows/platform.cpp
+++ b/client/windows/platform.cpp
@@ -693,21 +693,30 @@ void Platform::set_keyboard_lock_modifiers(uint32_t modifiers)
     }
 }
 
-#define KEY_BIT(keymap, key, bit) (keymap[key] & 0x80 ? bit : 0)
+typedef struct KeyboardModifier {
+    int vkey;
+    int bit;
+} KeyboardModifier;
+
+static const KeyboardModifier KEYBOARD_MODIFIERS[] = {
+    {VK_LSHIFT, Platform::L_SHIFT_MODIFIER},
+    {VK_RSHIFT, Platform::R_SHIFT_MODIFIER},
+    {VK_LCONTROL, Platform::L_CTRL_MODIFIER},
+    {VK_RCONTROL, Platform::R_CTRL_MODIFIER},
+    {VK_LMENU, Platform::L_ALT_MODIFIER},
+    {VK_RMENU, Platform::R_ALT_MODIFIER}};
 
 uint32_t Platform::get_keyboard_modifiers()
 {
-    BYTE keymap[256];
+    uint32_t modifiers_state = 0;
+    int num_modifiers = sizeof(KEYBOARD_MODIFIERS)/sizeof(KEYBOARD_MODIFIERS[0]);
 
-    if (!GetKeyboardState(keymap)) {
-        return 0;
+    for (int i = 0; i < num_modifiers; i++) {
+        short key_state = GetAsyncKeyState(KEYBOARD_MODIFIERS[i].vkey);
+        modifiers_state |= (key_state & 0x8000) ? KEYBOARD_MODIFIERS[i].bit : 0;
     }
-    return KEY_BIT(keymap, VK_LSHIFT, L_SHIFT_MODIFIER) |
-           KEY_BIT(keymap, VK_RSHIFT, R_SHIFT_MODIFIER) |
-           KEY_BIT(keymap, VK_LCONTROL, L_CTRL_MODIFIER) |
-           KEY_BIT(keymap, VK_RCONTROL, R_CTRL_MODIFIER) |
-           KEY_BIT(keymap, VK_LMENU, L_ALT_MODIFIER) |
-           KEY_BIT(keymap, VK_RMENU, R_ALT_MODIFIER);
+
+    return modifiers_state;
 }
 
 void Platform::reset_cursor_pos()