disallow '\n' and '\r' in tag names

add a test for disallowed characters in tag names

mercurial/commands.py

@@ -2002,8 +2002,10 b' def tag(ui, repo, name, rev=None, **opts'
     else:
         r = hex(repo.changelog.tip())
 
-    if name.find(revrangesep) >= 0:
-        raise util.Abort(_("'%s' cannot be used in a tag name") % revrangesep)
+    disallowed = (revrangesep, '\r', '\n')
+    for c in disallowed:
+        if name.find(c) >= 0:
+            raise util.Abort(_("%s cannot be used in a tag name") % repr(c))
 
     if opts['local']:
         repo.opener("localtags", "a").write("%s %s\n" % (r, name))

tests/test-tag

@@ -11,3 +11,7 b' hg history'
 echo foo >> .hgtags
 hg tag -d "0 0" "bleah2" || echo "failed"
 
+hg tag -l 'xx
+newline'
+hg tag -l 'xx:xx'
+true

tests/test-tag.out

@@ -18,3 +18,5 b' summary: test'
 
 abort: working copy of .hgtags is changed (please commit .hgtags manually)
 failed
+abort: '\n' cannot be used in a tag name
+abort: ':' cannot be used in a tag name