beautifygraph: don't warn about busted terminal if HGPLAIN is set

This was breaking some automation for users that discovered the
extension and turned it on.

Differential Revision: https://phab.mercurial-scm.org/D4338

hgext/beautifygraph.py

@@ -1,93 +1,93
 # -*- coding: UTF-8 -*-
 # beautifygraph.py - improve graph output by using Unicode characters
 #
 # Copyright 2018 John Stiles <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''beautify log -G output by using Unicode characters (EXPERIMENTAL)
 
    A terminal with UTF-8 support and monospace narrow text are required.
 '''
 
 from __future__ import absolute_import
 
 from mercurial.i18n import _
 from mercurial import (
     encoding,
     extensions,
     graphmod,
     templatekw,
 )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 def prettyedge(before, edge, after):
     if edge == '~':
         return '\xE2\x95\xA7' # U+2567 ╧
     if edge == 'X':
         return '\xE2\x95\xB3' # U+2573 ╳
     if edge == '/':
         return '\xE2\x95\xB1' # U+2571 ╱
     if edge == '-':
         return '\xE2\x94\x80' # U+2500 ─
     if edge == '|':
         return '\xE2\x94\x82' # U+2502 │
     if edge == ':':
         return '\xE2\x94\x86' # U+2506 ┆
     if edge == '\\':
         return '\xE2\x95\xB2' # U+2572 ╲
     if edge == '+':
         if before == ' ' and not after  == ' ':
             return '\xE2\x94\x9C' # U+251C ├
         if after  == ' ' and not before == ' ':
             return '\xE2\x94\xA4' # U+2524 ┤
         return '\xE2\x94\xBC' # U+253C ┼
     return edge
 
 def convertedges(line):
     line = ' %s ' % line
     pretty = []
     for idx in xrange(len(line) - 2):
         pretty.append(prettyedge(line[idx], line[idx + 1], line[idx + 2]))
     return ''.join(pretty)
 
 def getprettygraphnode(orig, *args, **kwargs):
     node = orig(*args, **kwargs)
     if node == 'o':
         return '\xE2\x97\x8B' # U+25CB ○
     if node == '@':
         return '\xE2\x97\x8D' # U+25CD ◍
     if node == '*':
         return '\xE2\x88\x97' # U+2217 ∗
     if node == 'x':
         return '\xE2\x97\x8C' # U+25CC ◌
     if node == '_':
         return '\xE2\x95\xA4' # U+2564 ╤
     return node
 
 def outputprettygraph(orig, ui, graph, *args, **kwargs):
     (edges, text) = zip(*graph)
     graph = zip([convertedges(e) for e in edges], text)
     return orig(ui, graph, *args, **kwargs)
 
 def extsetup(ui):
+    if ui.plain('graph'):
+        return
+
     if encoding.encoding != 'UTF-8':
         ui.warn(_('beautifygraph: unsupported encoding, UTF-8 required\n'))
         return
 
     if 'A' in encoding._wide:
         ui.warn(_('beautifygraph: unsupported terminal settings, '
                   'monospace narrow text required\n'))
         return
 
-    if ui.plain('graph'):
-        return
-
     extensions.wrapfunction(graphmod, 'outputgraph', outputprettygraph)
     extensions.wrapfunction(templatekw, 'getgraphnode', getprettygraphnode)