ipc: a modifier keysym is no key

Shift, Control, and their kin were mapped to special keys that the
engine then had a range and a check to ignore, and the GTK module made a
round trip to the daemon for each press.  ipckeysym maps them to key 0,
which was already the "no key" every frontend and the engine skip;
Kmodfirst, Kmodlast, and ismodkey go.

ipc.c

@@ -165,15 +165,17 @@ ipcconnect(void)
 
 /*
  * Engine key for an X keysym and its Unicode value: printable characters
- * as themselves, the function keysyms 0xff00-0xffff as Kspec+offset.
- * The keypad keys and Shift+Tab (ISO_Left_Tab) fold onto their plain
- * counterparts.
+ * as themselves, the function keysyms 0xff00-0xffff as Kspec+offset, and
+ * no key at all for a modifier.  The keypad keys and Shift+Tab
+ * (ISO_Left_Tab) fold onto their plain counterparts.
  */
 uint32_t
 ipckeysym(uint32_t sym, uint32_t unicode)
 {
 	if(unicode >= ' ' && unicode != 0x7f)
 		return unicode;
+	if(sym >= 0xffe1 && sym <= 0xffee)
+		return 0;
 	switch(sym){
 	case 0xfe20:
 	case 0xff89:

ipc.h

@@ -45,8 +45,6 @@ enum
 	Khenkan = Kspec|0x23,
 	Kkana = Kspec|0x27,
 	Kzenkaku = Kspec|0x2a,
-	Kmodfirst = Kspec|0xe1,
-	Kmodlast = Kspec|0xee,
 
 	/* X core modifier bits; GDK and IBus also flag Super at bit 26. */
 	Mshift = 1<<0,

strans.c

@@ -516,17 +516,11 @@ kokey(Rune c, u32int mod)
 	return c;
 }
 
-static int
-ismodkey(u32int ks)
-{
-	return ks >= Kmodfirst && ks <= Kmodlast;
-}
-
-/* Modifier presses and unmapped keys never engage the engine. */
+/* Modifier presses and unmapped keys, key 0, never engage the engine. */
 int
 keymeaningful(u32int ks)
 {
-	return ks != 0 && !ismodkey(ks);
+	return ks != 0;
 }
 
 static void

tests/engine_test.c

@@ -252,7 +252,7 @@ engine_active_owner_lifecycle(struct ct *t)
 	CT_EQ_PTR(t, nil, activeowner);
 	CT_EQ_INT(t, 0, im.pre.n);
 	CT_EQ_INT(t, 0, im.raw.n);
-	ownerrequest(&c, Keypress, Kmodfirst, 0);
+	ownerrequest(&c, Keypress, 0, 0);
 	CT_EQ_PTR(t, nil, activeowner);
 	res = ownerrequest(&c, Keypress, 'k', 0);
 	CT_EQ_PTR(t, &c, activeowner);
@@ -1646,7 +1646,7 @@ engine_emoji_preedit_languages(struct ct *t)
 	im.l = getlang(LangJP);
 	sclear(&com);
 	if(typekeys(t, "ka", &com)){
-		CT_CHECK(t, !keystroke(Kmodfirst+2, 0, &com));
+		CT_CHECK(t, !keystroke(0, 0, &com));
 		impre(&im, &shown);
 		checkstr(t, "modifier preserves Japanese", "か", &shown);
 		CT_CHECK(t, keystroke('E', Mctrl, &com));
@@ -1665,7 +1665,7 @@ engine_emoji_preedit_languages(struct ct *t)
 		CT_CHECK(t, keystroke('E', Mctrl, &com));
 		CT_EQ_INT(t, LangJP, im.l->lang);
 		CT_CHECK(t, keystroke('a', 0, &com));
-		CT_CHECK(t, !keystroke(Kmodfirst+2, 0, &com));
+		CT_CHECK(t, !keystroke(0, 0, &com));
 		CT_CHECK(t, search.lang);
 		checkstr(t, "modifier preserves search", "a", &search.text);
 		CT_CHECK(t, !keystroke('P', Mctrl|Mshift, &com));
@@ -2108,7 +2108,7 @@ engine_randomized_stress(struct ct *t)
 			res = ownerrequestat(owner, Keycaret, 0, 0, &pos);
 		else if(op == 24)
 			res = ownerrequest(owner, Keypress,
-				Kmodfirst + ((rnd >> 20) & 7), 0);
+				0, 0);
 		else if(op == 25)
 			res = ownerrequestat(owner, Keypress, 'p', Mctrl, &pos);
 		else if(op == 26)

tests/ipc_live_test.c

@@ -161,7 +161,7 @@ tryclient(char *path, int64_t deadline, int *client)
 	fd = connectsocket(path, deadline);
 	if(fd < 0)
 		return errno == ETIMEDOUT ? -1 : 0;
-	if(!sendkey(fd, 1, 0, Kmodfirst)){
+	if(!sendkey(fd, 1, 0, 0)){
 		close(fd);
 		return 0;
 	}
@@ -208,7 +208,7 @@ overflowrejected(char *path)
 	fd = connectsocket(path, deadline);
 	if(fd < 0)
 		return fail("overflow connect: %s", strerror(errno));
-	if(!sendkey(fd, 1, 0, Kmodfirst)){
+	if(!sendkey(fd, 1, 0, 0)){
 		close(fd);
 		return 1;
 	}
@@ -286,7 +286,7 @@ runcapacity(char *path)
 			fail("connect capacity client %d: %s", i, strerror(errno));
 			goto out;
 		}
-		if(!requestkey(client[i], 1, 0, Kmodfirst, 0, "", "",
+		if(!requestkey(client[i], 1, 0, 0, 0, "", "",
 		   "capacity modifier"))
 			goto out;
 	}

tests/ipc_test.c

@@ -60,6 +60,7 @@ ipc_masks_modifiers(struct ct *t)
 	CT_EQ_UINT(t, Kspec + 0xff, ipckeysym(0xffff, 0x7f));	/* Delete */
 	CT_EQ_UINT(t, 0x1f642, ipckeysym(0x101f642, 0x1f642));
 	CT_EQ_UINT(t, 0, ipckeysym(0xfe03, 0));	/* ISO_Level3_Shift */
+	CT_EQ_UINT(t, 0, ipckeysym(0xffe1, 0));	/* Shift_L */
 	CT_EQ_UINT(t, Mshift|Mctrl, ipcmod(Mshift|Mctrl|(1<<1)|(1<<4)));
 	CT_EQ_UINT(t, Msuper, ipcmod(1<<6));
 	CT_EQ_UINT(t, Msuper, ipcmod(1<<26));

tests/live.c

@@ -691,5 +691,5 @@ ipcprobe(int fd, char *where)
 {
 	unsigned char empty[] = {0, 0, 0, 0, 0};
 
-	return ipcrequest(fd, 0, Kmodfirst, empty, sizeof empty, where);
+	return ipcrequest(fd, 0, 0, empty, sizeof empty, where);
 }

tests/server_test.c

@@ -287,7 +287,7 @@ server_connection_ownership(struct ct *t)
 	CT_CHECK(t, readreply(t, &a, 1, "", preedit));
 	CT_EQ_STR(t, "", preedit);
 	CT_EQ_PTR(t, bowner, testengineowner());
-	if(!sendkey(t, &b, 1, 0, Kmodfirst))
+	if(!sendkey(t, &b, 1, 0, 0))
 		goto cleanup;
 	req = nextrequest(t, &f.pump, Keypress);
 	allowrequest(&f.pump);