Fix scoreboard keys dropping spectator follow mode

code/client/cl_input.cpp

@@ -1097,7 +1097,8 @@ static void CL_CmdButtons( usercmd_t *cmd ) {
 	// allow the game to know if any key at all is
 	// currently pressed, even if it isn't bound to anything
 	if ( anykeydown && !gameplayInputCaptured ) {
-		cmd->buttons |= BUTTON_ANY;
+		cmd->buttons |= clc.netchan.wireProfile == NETCHAN_WIRE_QL_RETAIL
+			? BUTTON_ANY : BUTTON_ANY_Q3;
 	}
 }
 

code/qcommon/q_shared.h

@@ -1322,7 +1322,10 @@ typedef struct playerState_s {
 #define BUTTON_PATROL		512
 #define BUTTON_FOLLOWME		1024
 
-#define	BUTTON_ANY			2048			// any key whatsoever
+// Retail CL_CmdButtons (0x004B5C67) uses bit 12 for key activity. Quake III's
+// bit 11 instead requests stop-follow in retail SpectatorThink (0x10033F82).
+#define	BUTTON_ANY			4096			// any key whatsoever
+#define BUTTON_ANY_Q3		2048			// retained Quake III wire profiles
 
 #define	MOVE_RUN			120			// if forwardmove or rightmove are >= MOVE_RUN,
 										// then BUTTON_WALKING should be set

docs/fnql/CHANGELOG.md

@@ -28,7 +28,7 @@ release, CI resets `Unreleased` for the next cycle.
 - _None yet._
 
 ### Fixes
-- _None yet._
+- Fixed scoreboard key presses unexpectedly leaving spectator follow mode.
 
 ### Documentation and Tooling
 - _None yet._

docs/fnql/INPUT_COMPATIBILITY.md

@@ -71,6 +71,46 @@ unchanged when neither correction applies.
 
 ## Usercmd sampling and stateful commands
 
+### Key activity and spectator follow
+
+Retail Quake Live uses `0x1000` for the engine's `BUTTON_ANY` key-activity
+flag. The inherited Quake III value, `0x0800`, is a separate stop-follow
+input in retail QL. Sending it for every physical key press made `+scores`
+bindings leave follow mode ([issue #5](https://github.com/themuffinator/FnQL/issues/5)).
+FnQL now emits the retail key-activity value for protocol 91 connections.
+Retained Quake III/ioquake3 wire profiles continue to use `BUTTON_ANY_Q3`
+(`0x0800`), preserving their existing key-activity behavior.
+
+Observed evidence, checked against the legitimate Steam build `1168251` on
+2026-09-24 and the [QLSRP reference corpus](https://github.com/themuffinator/QL-SRP):
+
+- `quakelive_steam.exe` `CL_CmdButtons` at `0x004B5BD0` masks catcher bit
+  `0x10` out for both `BUTTON_TALK` and key activity. At `0x004B5C67`, it
+  ORs `0x1000` into `usercmd_t.buttons`. Its SHA-256 is
+  `c926fe9f6c851e00b3b9332e88903ad01f28fdd60454873891c0158f5ded1299`.
+- Retail `bin.pk3`'s `qagamex86.dll` `SpectatorThink` tests a rising `0x0800`
+  edge at `0x10033F82`/`0x10033F89`, then calls `StopFollowing` at
+  `0x10033FB1`. Its SHA-256 is
+  `9bfad1b5df4cbbb3fcfb20781024fc5c0abe73ba8389c2f20be8c0a55552e83d`.
+- QLSRP's reconstructed `q_shared.h` still defines `BUTTON_ANY` as `2048`;
+  the retail instructions above take precedence over that source definition.
+
+These facts explain the reported distinction between console commands and
+physical bindings: console `+scores` does not create a key-activity edge.
+Holding another key already asserts the old flag, so the scoreboard key does
+not create another rising edge. This explanation is an inference from the
+report and the retail instructions, not a Proton runtime reproduction.
+
+The correction keeps the scoreboard's `0x10` catcher transparent to movement,
+preserves held-key state and command routing, and leaves explicit button bits
+and their wire encoding intact. The ABI assertion and successive usercmd codec
+tests reject the old value and cover press/hold/release, attack/walk chords,
+chat, the separate `0x0800` input, and the legacy key-activity value.
+Existing scoreboard/input tests protect
+the catcher behavior. Interactive Proton/Wayland validation remains pending.
+
+### Sampling and command delivery
+
 Relative mouse deltas do not carry timestamps in the engine ABI. When usercmd
 generation is suspended before a gamestate, while disconnected, or by a local
 pause, FnQL therefore discards deltas collected during that unsampleable gap

docs/fnql/RELEASE_COMPLETION.md

@@ -23,6 +23,12 @@ only planned.
 
 ## Ready For Changelog
 
+- [x] Correct the engine's key-activity button to retail Quake Live's `0x1000`,
+  preventing scoreboard key presses from emitting the separate `0x0800`
+  stop-follow input while retaining Quake III wire-profile behavior.
+  Retail executable/module inspection and ABI/usercmd
+  regression tests cover the correction; interactive Proton validation is
+  still pending. See [input compatibility](INPUT_COMPATIBILITY.md#key-activity-and-spectator-follow).
 - [x] Make pending WebUI avatars use a steady-clock retry backoff and immediate
   availability hints from Steam, with four distinct image paths per frame.
   Duplicate requests share provider/PNG work and successful buffers; navigation

tests/message_codec_tests.cpp

@@ -88,6 +88,58 @@ int TestWireProfileUserCommandHash() {
 	return 0;
 }
 
+int TestRetailAnyKeyButtons() {
+	struct ButtonSample {
+		int buttons;
+		int expected;
+	};
+	// A scoreboard/unbound key must report activity without asserting retail's
+	// stop-follow bit (0x0800). Exercise presses, holds, releases, chords, and
+	// an explicit stop-follow bit across successive delta baselines.
+	const ButtonSample samples[] = {
+		{ 0, 0 },
+		{ BUTTON_ANY, 0x1000 },
+		{ BUTTON_ANY, 0x1000 },
+		{ 0, 0 },
+		{ BUTTON_ANY | BUTTON_ATTACK, 0x1001 },
+		{ BUTTON_ANY | BUTTON_WALKING, 0x1010 },
+		{ BUTTON_ANY, 0x1000 },
+		{ 0, 0 },
+		{ 0x0800, 0x0800 },
+		{ BUTTON_ANY | 0x0800, 0x1800 },
+		{ BUTTON_TALK, 0x0002 },
+		{ 0, 0 },
+		// Retained Quake III/ioquake3 connections keep their original flag.
+		{ BUTTON_ANY_Q3, 0x0800 },
+		{ BUTTON_ANY_Q3 | BUTTON_ATTACK, 0x0801 },
+		{ BUTTON_ANY_Q3 | BUTTON_WALKING, 0x0810 },
+		{ 0, 0 },
+	};
+	std::array<byte, 64> storage{};
+	usercmd_t baseline{};
+	for ( const ButtonSample& sample : samples ) {
+		usercmd_t sent = baseline;
+		sent.serverTime += 16;
+		sent.buttons = sample.buttons;
+		usercmd_t received{};
+		msg_t writer{};
+		MSG_Init( &writer, storage.data(), static_cast<int>( storage.size() ) );
+		MSG_WriteDeltaUsercmdKey( &writer, 0x10203040, &baseline, &sent );
+		CHECK( !writer.overflowed );
+
+		msg_t reader{};
+		MSG_Init( &reader, storage.data(), static_cast<int>( storage.size() ) );
+		reader.cursize = writer.cursize;
+		MSG_BeginReading( &reader );
+		MSG_ReadDeltaUsercmdKey( &reader, 0x10203040, &baseline, &received );
+		CHECK( received.buttons == sample.expected );
+		CHECK( received.serverTime == sent.serverTime );
+		CHECK( reader.readcount <= reader.cursize );
+		baseline = received;
+	}
+	return 0;
+}
+
 int TestWireProfileCommandStrings() {
 	static const char command[] = { 'p', 'r', 'i', 'n', 't', ' ', '"',
 		'c', 'a', 'f', '\xc3', '\xa9', ' ', '%', '"', '\0' };
@@ -286,6 +338,7 @@ int TestPlayerStateRoundTrip() {
 int main() {
 	if ( const int result = TestBounds() ) return result;
 	if ( const int result = TestWireProfileUserCommandHash() ) return result;
+	if ( const int result = TestRetailAnyKeyButtons() ) return result;
 	if ( const int result = TestWireProfileCommandStrings() ) return result;
 	if ( const int result = TestUserCommandRoundTrip() ) return result;
 	if ( const int result = TestUserCommandClockWrap() ) return result;

tests/protocol_layout_tests.cpp

@@ -12,6 +12,12 @@ static_assert( offsetof( usercmd_t, forwardmove ) == 23 );
 static_assert( offsetof( usercmd_t, rightmove ) == 24 );
 static_assert( offsetof( usercmd_t, upmove ) == 25 );
 
+// Retail CL_CmdButtons (0x004B5C67) emits bit 12 for key activity.
+// Bit 11 is a separate stop-follow input in retail SpectatorThink.
+static_assert( BUTTON_ANY == 0x1000 );
+static_assert( ( BUTTON_ANY & 0x0800 ) == 0 );
+static_assert( BUTTON_ANY_Q3 == 0x0800 );
+
 static_assert( sizeof( trajectory_t ) == 40 );
 static_assert( offsetof( trajectory_t, gravity ) == 36 );