Make escaping consistent for fish <-> fishd protocol

Fix fork guards to work in fishd
https://github.com/fish-shell/fish-shell/issues/339

env.cpp

@@ -375,7 +375,7 @@ static void react_to_variable_change(const wcstring &key) {
    Universal variable callback function. This function makes sure the
    proper events are triggered when an event occurs.
 */
-static void universal_callback( int type,
+static void universal_callback( fish_message_type_t type,
 								const wchar_t *name, 
 								const wchar_t *val )
 {
@@ -395,6 +395,9 @@ static void universal_callback( int type,
 			str=L"ERASE";
 			break;
 		}
+        
+		default:
+		    break;
 	}
 	
 	if( str )

env_universal.cpp

@@ -61,7 +61,7 @@ static int get_socket_count = 0;
 static wchar_t * path;
 static wchar_t *user;
 static void (*start_fishd)();
-static void (*external_callback)( int type, const wchar_t *name, const wchar_t *val );
+static void (*external_callback)( fish_message_type_t type, const wchar_t *name, const wchar_t *val );
 
 /**
    Flag set to 1 when a barrier reply is recieved
@@ -165,7 +165,7 @@ static int get_socket( int fork_ok )
 /**
    Callback function used whenever a new fishd message is recieved
 */
-static void callback( int type, const wchar_t *name, const wchar_t *val )
+static void callback( fish_message_type_t type, const wchar_t *name, const wchar_t *val )
 {	
 	if( type == BARRIER_REPLY )
 	{
@@ -250,7 +250,7 @@ static void reconnect()
 void env_universal_init( wchar_t * p, 
 						 wchar_t *u, 
 						 void (*sf)(),
-						 void (*cb)( int type, const wchar_t *name, const wchar_t *val ))
+						 void (*cb)( fish_message_type_t type, const wchar_t *name, const wchar_t *val ))
 {
 	path=p;
 	user=u;

env_universal.h

@@ -20,7 +20,7 @@ extern connection_t env_universal_server;
 void env_universal_init( wchar_t * p, 
                         wchar_t *u, 
                         void (*sf)(),
-                        void (*cb)( int type, const wchar_t *name, const wchar_t *val ));
+                        void (*cb)( fish_message_type_t type, const wchar_t *name, const wchar_t *val ));
 /**
   Free memory used by envuni
 */

env_universal_common.cpp

@@ -112,7 +112,7 @@ env_var_table_t env_universal_var;
 /**
    Callback function, should be called on all events
 */
-void (*callback)( int type, 
+static void (*callback)( fish_message_type_t type,
 				  const wchar_t *key, 
 				  const wchar_t *val );
 
@@ -405,7 +405,7 @@ static char *wcs2utf( const wchar_t *in )
 
 
 
-void env_universal_common_init( void (*cb)(int type, const wchar_t *key, const wchar_t *val ) )
+void env_universal_common_init( void (*cb)(fish_message_type_t type, const wchar_t *key, const wchar_t *val ) )
 {
 	callback = cb;
 }
@@ -592,7 +592,7 @@ void env_universal_common_set( const wchar_t *key, const wchar_t *val, int expor
 /**
    Parse message msg
 */
-static void parse_message( wchar_t *msg, 
+static void parse_message( wchar_t *msg,
 						   connection_t *src )
 {
 //	debug( 3, L"parse_message( %ls );", msg );
@@ -622,7 +622,8 @@ static void parse_message( wchar_t *msg,
 			val = tmp+1;
 			val = unescape( val, 0 );
 			
-			env_universal_common_set( key, val, exportv );
+			if (key && val)
+			    env_universal_common_set( key, val, exportv );
 			
 			free( val );
 			free( key );
@@ -752,6 +753,15 @@ void try_send_all( connection_t *c )
 	}
 }
 
+/* The universal variable format has some funny escaping requirements; here we try to be safe */
+static bool is_universal_safe_to_encode_directly(wchar_t c)
+{
+    if (c < 32 || c > 128)
+        return false;
+    
+    return iswalnum(c) || wcschr(L"/", c);
+}
+
 /**
    Escape specified string
  */
@@ -760,21 +770,22 @@ static wcstring full_escape( const wchar_t *in )
 	wcstring out;
 	for( ; *in; in++ )
 	{
-		if( *in < 32 )
+        wchar_t c = *in;
+        if (is_universal_safe_to_encode_directly(c))
+        {
+            out.push_back(c);
+        }
+		else if (c < 256)
 		{
-			append_format( out, L"\\x%.2x", *in );
+			append_format(out, L"\\x%.2x", c);
 		}
-		else if( *in < 128 )
+		else if (c < 65536)
 		{
-			out.push_back(*in);
+			append_format(out, L"\\u%.4x", c);
-		}
-		else if( *in < 65536 )
-		{
-			append_format( out, L"\\u%.4x", *in );
 		}
 		else
 		{
-			append_format( out, L"\\U%.8x", *in );
+			append_format(out, L"\\U%.8x", c);
 		}
 	}
 	return out;
@@ -803,7 +814,7 @@ void set_body(message_t *msg, ...)
 }
 
 /* Returns an instance of message_t allocated via new */
-message_t *create_message( int type,
+message_t *create_message( fish_message_type_t type,
                           const wchar_t *key_in,
                           const wchar_t *val_in )
 {

env_universal_common.h

@@ -40,15 +40,14 @@
 /**
    The different types of commands that can be sent between client/server
 */
-enum
+typedef enum
 {
 	SET,
 	SET_EXPORT,
 	ERASE,
 	BARRIER,
 	BARRIER_REPLY,
-}
+} fish_message_type_t;
-	;
 
 /**
    The size of the buffer used for reading from the socket
@@ -133,12 +132,12 @@ void try_send_all( connection_t *c );
 /**
    Create a messge with the specified properties
 */
-message_t *create_message( int type, const wchar_t *key, const wchar_t *val );
+message_t *create_message( fish_message_type_t type, const wchar_t *key, const wchar_t *val );
 
 /**
    Init the library
 */
-void env_universal_common_init(void (*cb)(int type, const wchar_t *key, const wchar_t *val ) );
+void env_universal_common_init(void (*cb)(fish_message_type_t type, const wchar_t *key, const wchar_t *val ) );
 
 /**
    Destroy library data

fish.cpp

@@ -410,10 +410,34 @@ static int fish_parse_opt( int argc, char **argv, const char **cmd_ptr )
    parses commands from stdin or files, depending on arguments
 */
 
+static wcstring full_escape( const wchar_t *in )
+{
+	wcstring out;
+	for( ; *in; in++ )
+	{
+		if( *in < 32 )
+		{
+			append_format( out, L"\\x%.2x", *in );
+		}
+		else if( *in < 128 )
+		{
+			out.push_back(*in);
+		}
+		else if( *in < 65536 )
+		{
+			append_format( out, L"\\u%.4x", *in );
+		}
+		else
+		{
+			append_format( out, L"\\U%.8x", *in );
+		}
+	}
+	return out;
+}
+
 extern int g_fork_count;
 int main( int argc, char **argv )
 {    
-    struct stat tmp;
 	int res=1;
 	const char *cmd=0;
 	int my_optind=0;
@@ -425,7 +449,8 @@ int main( int argc, char **argv )
 	is_interactive_session=1;
 	program_name=L"fish";
 
-    stat("----------FISH_HIT_MAIN----------", &tmp);
+    //struct stat tmp;
+    //stat("----------FISH_HIT_MAIN----------", &tmp);
 
 	my_optind = fish_parse_opt( argc, argv, &cmd );
 

fishd.cpp

@@ -496,7 +496,7 @@ unlock:
 /**
    Event handler. Broadcasts updates to all clients.
 */
-static void broadcast( int type, const wchar_t *key, const wchar_t *val )
+static void broadcast( fish_message_type_t type, const wchar_t *key, const wchar_t *val )
 {
 	connection_t *c;
 	message_t *msg;
@@ -540,6 +540,9 @@ static void daemonize()
 			
 		case 0:
 		{
+			/* Ordinarily there's very limited things we will do after fork, due to multithreading. But fishd is safe because it's single threaded. So don't die in is_forked_child. */
+			setup_fork_guards();
+        
 			/*
 			  Make fishd ignore the HUP signal.
 			*/
@@ -557,6 +560,7 @@ static void daemonize()
 			act.sa_handler=&handle_term;
 			sigaction( SIGTERM, &act, 0);
 			break;
+            
 		}
 		
 		default: