view tests/test-template-engine.t @ 28261:2ab59ac06b76

chg: detect chg started by chg

Sometimes people may create a symbol link from hg to chg, or write a wrapper
script named hg calling chg. Without $HG and $CHGHG set, this will lead to
chg executes itself causing deadlock. The user will notice chg hangs for some
time and aborts with a timed out message, without knowing the root cause and
how to solve it.

This patch sets a dummy environment variable before executing hg to detect
this situation, and print a fatal message with some possible solutions.

CHGINTERNALMARK is set by chg client to detect the situation that chg is
started by chg. It is temporary and should be dropped to avoid possible
side effects.

  $ cat > engine.py << EOF
  > 
  > from mercurial import templater
  > 
  > class mytemplater(object):
  >     def __init__(self, loader, filters, defaults):
  >         self.loader = loader
  > 
  >     def process(self, t, map):
  >         tmpl = self.loader(t)
  >         for k, v in map.iteritems():
  >             if k in ('templ', 'ctx', 'repo', 'revcache', 'cache'):
  >                 continue
  >             if hasattr(v, '__call__'):
  >                 v = v(**map)
  >             v = templater.stringify(v)
  >             tmpl = tmpl.replace('{{%s}}' % k, v)
  >         yield tmpl
  > 
  > templater.engines['my'] = mytemplater
  > EOF
  $ hg init test
  $ echo '[extensions]' > test/.hg/hgrc
  $ echo "engine = `pwd`/engine.py" >> test/.hg/hgrc
  $ cd test
  $ cat > mymap << EOF
  > changeset = my:changeset.txt
  > EOF
  $ cat > changeset.txt << EOF
  > {{rev}} {{node}} {{author}}
  > EOF
  $ hg ci -Ama
  adding changeset.txt
  adding mymap
  $ hg log --style=./mymap
  0 97e5f848f0936960273bbf75be6388cd0350a32b test

  $ cat > changeset.txt << EOF
  > {{p1rev}} {{p1node}} {{p2rev}} {{p2node}}
  > EOF
  $ hg ci -Ama
  $ hg log --style=./mymap
  0 97e5f848f0936960273bbf75be6388cd0350a32b -1 0000000000000000000000000000000000000000
  -1 0000000000000000000000000000000000000000 -1 0000000000000000000000000000000000000000

  $ cd ..