Fix Xkb handling on certain systems.

On some systems XTEST events are delivered via a special input device
that may be configured with a different keymap than the physical keyboard.
This patch fixes the keycode lookup to take the XTEST device into account.

1 files changed, 71 insertions, 6 deletions

diff --git a/src/input/x11FakeKeyboardHandler.cpp b/src/input/x11FakeKeyboardHandler.cpp
index 95e83ab..82cc437 100644
--- a/src/input/x11FakeKeyboardHandler.cpp
+++ b/src/input/x11FakeKeyboardHandler.cpp
@@ -26,6 +26,7 @@
 #include <X11/keysym.h>
 #include <X11/keysymdef.h>
 #include <X11/extensions/XTest.h>
+#include <X11/extensions/XInput2.h>
 #include <X11/XKBlib.h>
 #include <src/util/consoleLogger.h>
 #include "x11InputUtils.h"
@@ -502,14 +503,64 @@ void initialize_basic_keycodes()
 	}
 	else
 	{
+		// Try to find out what device XTest will send events on:
+		int xkbDeviceId = XkbUseCoreKbd;
+		Atom xtestDeviceProp = XInternAtom(dpy, "XTEST Device", false);
+		int ndevinfos;
+		XIDeviceInfo* devinfos = XIQueryDevice(dpy, XIAllDevices, &ndevinfos);
+		if(devinfos)
+		{
+			for(int i = 0; i < ndevinfos && xkbDeviceId == XkbUseCoreKbd; i++)
+			{
+				XIDeviceInfo* devinfo = devinfos + i;
+				qDebug("Found device of type %d with name %s", devinfo->use, devinfo->name);
+
+				// We want it to be a keyboard.
+				if(devinfo->use != XIMasterKeyboard && devinfo->use != XISlaveKeyboard)
+					continue;
+
+				int nprops;
+				Atom* props = XIListProperties(dpy, devinfo->deviceid, &nprops);
+				if(props)
+				{
+					for(int j = 0; j < nprops && xkbDeviceId == XkbUseCoreKbd; j++)
+					{
+						Atom prop = props[j];
+						if(prop == xtestDeviceProp)
+						{
+							// The device is the XTest Keyboard:
+							xkbDeviceId = devinfo->deviceid;
+						}
+					}
+					XFree(props);
+				}
+			}
+			XIFreeDeviceInfo(devinfos);
+		}
+
+		// Okay, we know which device to query. Now get its keymap:
+		XkbDescPtr keybDesc = XkbGetKeyboard(dpy, XkbAllComponentsMask, xkbDeviceId);
+		if(!keybDesc)
+		{
+			qWarning("Unable to retrieve keyboard description for device %d. Falling back to unreliable global mapping", xkbDeviceId);
+		}
+
 		for(int i = min_keycode; i <= max_keycode; i++)
 		{
 			for(int j = 0; j <= 0xff; j++)
 			{
 				KeySym ks = 0;
 				unsigned int unconsumed;
-				if(!XkbLookupKeySym(dpy, i, j, &unconsumed, &ks) || ks == NoSymbol)
-					continue;
+				if(keybDesc)
+				{
+					if(!XkbTranslateKeyCode(keybDesc, i, j, &unconsumed, &ks) || ks == NoSymbol)
+						continue;
+				}
+				else
+				{
+					if(!XkbLookupKeySym(dpy, i, j, &unconsumed, &ks) || ks == NoSymbol)
+						continue;
+				}
 
 				if(ks && (ks < 0x100))
 				{
@@ -527,6 +578,12 @@ void initialize_basic_keycodes()
 				}
 			}
 		}
+
+		// Free the keyboard description:
+		if(keybDesc)
+		{
+			XkbFreeKeyboard(keybDesc, XkbAllComponentsMask, true);
+		}
 	}
 
 	// find out which keycodes cause the modifier state bits:
@@ -750,10 +807,18 @@ void X11FakeKeyboardHandler::handle(InputEvent const& evt)
 						xmodifier_type mods = translate_modifiers(evt.qt_modifiers());
 
 						// we may need to press additional modifiers to generate this keysym:
-						// but, since we do not differentiate upper and lower case,
-						// and instead let the sender handle those modifiers,
-						// we need to AND ShiftModifier and LockModifier out.
-						mods |= basic_modifiers[ks] & ~(1<<ShiftMapIndex) & ~(1<<LockMapIndex);
+						if(isalpha(ks))
+						{
+							// but, since we do not differentiate upper and lower case,
+							// and instead let the sender handle those modifiers,
+							// we need to AND ShiftModifier and LockModifier out.
+							mods |= basic_modifiers[ks] & ~(1<<ShiftMapIndex) & ~(1<<LockMapIndex);
+						}
+						else
+						{
+							// Not an alpha character. We do need to respect Shift and Lock for those:
+							mods |= basic_modifiers[ks];
+						}
 
 						// now, tweak the modifiers
 						tweak_sequence_type tweaks;