codereview: no LGTM needed for doc/go1.x.txt

Rob asked for this change to make maintaining go1.4.txt easier.
If you are not sure of a change, it is still okay to send for review.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/109880044

lib/codereview/codereview.py

@@ -1937,7 +1937,7 @@ def submit(ui, repo, *pats, **opts):
 
 	about = ""
 
-	if not cl.lgtm and not opts.get('tbr') and not isAddca(cl):
+	if not cl.lgtm and not opts.get('tbr') and needLGTM(cl):
 		raise hg_util.Abort("this CL has not been LGTM'ed")
 	if cl.lgtm:
 		about += "LGTM=" + JoinComma([CutDomain(who) for (who, line, approval) in cl.lgtm if approval]) + "\n"
@@ -2052,10 +2052,20 @@ def submit(ui, repo, *pats, **opts):
 			return err
 	return 0
 
-def isAddca(cl):
+def needLGTM(cl):
 	rev = cl.reviewer
 	isGobot = 'gobot' in rev or 'gobot@swtch.com' in rev or 'gobot@golang.org' in rev
-	return cl.desc.startswith('A+C:') and 'Generated by addca.' in cl.desc and isGobot
+	
+	# A+C CLs generated by addca do not need LGTM
+	if cl.desc.startswith('A+C:') and 'Generated by addca.' in cl.desc and isGobot:
+		return False
+	
+	# CLs modifying only go1.x.txt do not need LGTM
+	if len(cl.files) == 1 and cl.files[0].startswith('doc/go1.') and cl.files[0].endswith('.txt'):
+		return False
+	
+	# Other CLs need LGTM
+	return True
 
 #######################################################################
 # hg sync