fix: assign one active engine owner

ipc.h

@@ -6,7 +6,10 @@
 #define IPCPATH "/tmp/strans.%d"
 
 /*
- * Request: [want-preedit, modifiers, key byte 0, ..., key byte 3].
+ * Request: [flags, modifiers, key byte 0, ..., key byte 3].
+ * Flags request preedit and distinguish lifecycle reset from physical Escape.
+ * The server assigns the connection's owner generation; it is not sent on
+ * the wire.
  * Only Mmask modifier bits are retained.
  * Response: [eaten, commit-length-low, commit-length-high, commit...],
  * followed, when requested, by
@@ -16,6 +19,9 @@
 
 enum
 {
+	Ipcreqwant = 1<<0,
+	Ipcreqreset = 1<<1,
+
 	Kspec = 0x110000,
 	Kback = Kspec|0x08,
 	Ktab = Kspec|0x09,
@@ -48,7 +54,9 @@ struct Ipcresp
 };
 
 void	ipcpackreq(unsigned char[Ipcreqsz], int, unsigned int, unsigned int);
+void	ipcpackreset(unsigned char[Ipcreqsz], int);
 void	ipcunpackreq(const unsigned char[Ipcreqsz], int*, unsigned int*, unsigned int*);
+int	ipcreqreset(const unsigned char[Ipcreqsz]);
 int	ipcpackresp(unsigned char*, size_t, int, const char*, size_t, const char*, size_t, int);
 int	ipcreadn(int, void*, size_t);
 int	ipcsend(int, const void*, size_t);