[PATCH xserver] xkb: fix releasing overlay while keydown

[Mihail Konev]

The overlay_keys array could be avoided.

Testcase:

// In the exact order:
// - press Insert
// - press Tilde
// - release Insert
// - wait
// - release Tilde
//
// Keyboard input would be locked.

xkb_keymap {
        xkb_keycodes { include "evdev" };
        xkb_types    { include "complete" };

        xkb_compat   { include "complete"
             interpret Overlay1_Enable+AnyOfOrNone(all) {
                action= SetControls(controls=Overlay1);
             };
        };

        xkb_symbols  { include "pc+inet(evdev)+us"
                key <INS> { [ Overlay1_Enable ] };
                key <AE01> { overlay1 = <AE02> }; // Insert+1 => 2
                key <TLDE> { overlay1 = <I128> }; // Insert+~ => XF86LaunchA
        };

        xkb_geometry { include "pc(pc104)" };
};

Signed-off-by: Mihail Konev <k.mvc at ya.ru>
---

Seems to work.
The comment is not fully correct, as one needs to also match the Tilde
presses while "- wait"-ing, and not only the "- release Tilde".

overlay_keys array duplicates overlay1= and overlay2=, but I have no idea
where to find these in Xkb.


 xkb/xkbPrKeyEv.c | 54 +++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 43 insertions(+), 11 deletions(-)

diff --git a/xkb/xkbPrKeyEv.c b/xkb/xkbPrKeyEv.c
index f7a6b4b14306..dc66ca8bd740 100644
--- a/xkb/xkbPrKeyEv.c
+++ b/xkb/xkbPrKeyEv.c
@@ -43,6 +43,9 @@ THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 /***====================================================================***/
 
+static unsigned char overlay_in_effect[256];
+static unsigned int overlay_keys[2][256];
+
 void
 XkbProcessKeyboardEvent(DeviceEvent *event, DeviceIntPtr keybd)
 {
@@ -51,6 +54,7 @@ XkbProcessKeyboardEvent(DeviceEvent *event, DeviceIntPtr keybd)
     int key;
     XkbBehavior behavior;
     unsigned ndx;
+    unsigned effective_overlay = 0;
 
     xkbi = keyc->xkbInfo;
     key = event->detail.key;
@@ -68,6 +72,16 @@ XkbProcessKeyboardEvent(DeviceEvent *event, DeviceIntPtr keybd)
     /* do anything to implement the behavior, but it *does* report that */
     /* key is hardwired */
 
+    {
+        if (key >= 0 && key < 256) {
+            effective_overlay = overlay_in_effect[key];
+            switch (effective_overlay) {
+                case 1: behavior.type = XkbKB_Overlay1; break;
+                case 2: behavior.type = XkbKB_Overlay1; break;
+            }
+        }
+    }
+
     if (!(behavior.type & XkbKB_Permanent)) {
         switch (behavior.type) {
         case XkbKB_Default:
@@ -121,20 +135,38 @@ XkbProcessKeyboardEvent(DeviceEvent *event, DeviceIntPtr keybd)
         case XkbKB_Overlay2:
         {
             unsigned which;
+            unsigned which_overlay;
+            unsigned overlay_enabled;
+            unsigned behavior_data = behavior.data;
 
-            if (behavior.type == XkbKB_Overlay1)
+            if (behavior.type == XkbKB_Overlay1) {
                 which = XkbOverlay1Mask;
-            else
+                which_overlay = 1;
+            } else {
                 which = XkbOverlay2Mask;
-            if ((xkbi->desc->ctrls->enabled_ctrls & which) == 0)
-                break;
-            if ((behavior.data >= xkbi->desc->min_key_code) &&
-                (behavior.data <= xkbi->desc->max_key_code)) {
-                event->detail.key = behavior.data;
-                /* 9/11/94 (ef) -- XXX! need to match release with */
-                /*                 press even if the state of the  */
-                /*                 corresponding overlay control   */
-                /*                 changes while the key is down   */
+                which_overlay = 2;
+            }
+
+            overlay_enabled = (xkbi->desc->ctrls->enabled_ctrls & which);
+
+            ErrorF("[xkb] key:%d %c ov:%d ov_enabled:%d eov:%d\n",
+                    key,
+                    ((event->type == ET_KeyPress) ? '_' : '^'),
+                    which_overlay, overlay_enabled, effective_overlay);
+
+            if (!overlay_enabled && event->type == ET_KeyRelease)
+                overlay_in_effect[(unsigned char)key] = 0;
+            else
+                overlay_in_effect[(unsigned char)key] = which_overlay;
+
+            if (overlay_enabled)
+                overlay_keys[which_overlay][(unsigned char)key] = behavior.data;
+            else
+                behavior_data = overlay_keys[which_overlay][(unsigned char)key];
+
+            if ((behavior_data >= xkbi->desc->min_key_code) &&
+                (behavior_data <= xkbi->desc->max_key_code)) {
+                event->detail.key = behavior_data;
             }
         }
             break;
-- 
2.9.2