xgb: fix request length and request size.

R=nigeltao_golang, rsc
CC=golang-dev
https://golang.org/cl/759041

src/pkg/xgb/go_client.py

@@ -8,6 +8,7 @@ from os.path import basename, exists
 import getopt
 import sys
 import re
+import math
 
 _ns = None
 
@@ -345,20 +346,22 @@ def go_complex_writer(self, name, void):
 		go('func (c *Conn) %sRequest(', func_name)
 		go_complex_writer_arguments(param_fields, "Cookie {")
 	
-	fixedtotal = structsize(self.fields)
-	if fixedtotal <= 32:
-		go('	b := c.scratch[0:%d]', fixedtotal)
+	fixedlength = math.ceil(float(structsize(self.fields)) / float(4))
+	fixedsize = fixedlength * 4
+	
+	if fixedsize <= 32:
+		go('	b := c.scratch[0:%d]', fixedsize)
 	else:
-		go('	b := make([]byte, %d)', fixedtotal)
+		go('	b := make([]byte, %d)', fixedsize)
 	firstvar = 0
 	for field in wire_fields:
 		if not field.type.fixed_size():
 			if not firstvar:
 				firstvar = 1
-				go('	n := %d', fixedtotal)
+				go('	n := %d', fixedsize)
 			go('	n += pad(%s * %d)', go_accessor_expr(field.type.expr, '', True), field.type.size)
 	if not firstvar:
-		go('	put16(b[2:], %d)', fixedtotal / 4)
+		go('	put16(b[2:], %d)', fixedlength)
 	else:
 		go('	put16(b[2:], uint16(n / 4))')
 	go('	b[0] = %s', self.opcode)
@@ -662,7 +665,7 @@ output = {'open'	: go_open,
 		  'enum'	: go_enum,
 		  'struct'	: go_struct,
 		  'union'	: go_union,
-		  'request' : go_request,
+		  'request'	: go_request,
 		  'event'	: go_event,
 		  'error'	: go_error
 		  }

src/pkg/xgb/xproto.go

@@ -2427,8 +2427,8 @@ func (c *Conn) ListFontsWithInfoReply(cookie Cookie) (*ListFontsWithInfoReply, o
 }
 
 func (c *Conn) SetFontPath(FontQty uint16, Path []byte) {
-	b := c.scratch[0:6]
-	n := 6
+	b := c.scratch[0:8]
+	n := 8
 	n += pad(len(Path) * 1)
 	put16(b[2:], uint16(n/4))
 	b[0] = 51
@@ -3553,8 +3553,8 @@ func (c *Conn) ListExtensionsReply(cookie Cookie) (*ListExtensionsReply, os.Erro
 }
 
 func (c *Conn) ChangeKeyboardMapping(KeycodeCount byte, FirstKeycode byte, KeysymsPerKeycode byte, Keysyms []Keysym) {
-	b := c.scratch[0:6]
-	n := 6
+	b := c.scratch[0:8]
+	n := 8
 	n += pad((int(KeycodeCount) * int(KeysymsPerKeycode)) * 4)
 	put16(b[2:], uint16(n/4))
 	b[0] = 100
@@ -3566,8 +3566,8 @@ func (c *Conn) ChangeKeyboardMapping(KeycodeCount byte, FirstKeycode byte, Keysy
 }
 
 func (c *Conn) GetKeyboardMappingRequest(FirstKeycode byte, Count byte) Cookie {
-	b := c.scratch[0:6]
-	put16(b[2:], 1)
+	b := c.scratch[0:8]
+	put16(b[2:], 2)
 	b[0] = 101
 	b[4] = FirstKeycode
 	b[5] = Count
@@ -3733,8 +3733,8 @@ const (
 )
 
 func (c *Conn) SetScreenSaver(Timeout int16, Interval int16, PreferBlanking byte, AllowExposures byte) {
-	b := c.scratch[0:10]
-	put16(b[2:], 2)
+	b := c.scratch[0:12]
+	put16(b[2:], 3)
 	b[0] = 107
 	put16(b[4:], uint16(Timeout))
 	put16(b[6:], uint16(Interval))