# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1462576618 -3600
# Node ID ad1bdea43965ec3d14d6a343bbec4e289208949c
# Parent  fe50341de1fff843ae633d7ad7be908100c09cdc
dispatch: defer environment variable resolution in alias commands (BC)

Before this patch, if there are environment variables in an alias command,
they will be expanded immediately when we first see the alias.

This will cause issues with chg, because environment variable updates will
not propagate to expanded arguments.

This patch makes "args" of "cmdalias" a property that will be calculated
every time when accessed.

diff -r fe50341de1ff -r ad1bdea43965 mercurial/dispatch.py
--- a/mercurial/dispatch.py	Tue May 03 16:33:25 2016 -0400
+++ b/mercurial/dispatch.py	Sat May 07 00:16:58 2016 +0100
@@ -384,7 +384,7 @@
         self.cmdname = ''
         self.definition = definition
         self.fn = None
-        self.args = []
+        self.givenargs = []
         self.opts = []
         self.help = ''
         self.badalias = None
@@ -432,7 +432,7 @@
                              % (self.name, inst))
             return
         self.cmdname = cmd = args.pop(0)
-        args = map(util.expandpath, args)
+        self.givenargs = args
 
         for invalidarg in ("--cwd", "-R", "--repository", "--repo", "--config"):
             if _earlygetopt([invalidarg], args):
@@ -448,7 +448,6 @@
             else:
                 self.fn, self.opts = tableentry
 
-            self.args = aliasargs(self.fn, args)
             if self.help.startswith("hg " + cmd):
                 # drop prefix in old-style help lines so hg shows the alias
                 self.help = self.help[4 + len(cmd):]
@@ -462,6 +461,11 @@
             self.badalias = (_("alias '%s' resolves to ambiguous command '%s'")
                              % (self.name, cmd))
 
+    @property
+    def args(self):
+        args = map(util.expandpath, self.givenargs)
+        return aliasargs(self.fn, args)
+
     def __getattr__(self, name):
         adefaults = {'norepo': True, 'optionalrepo': False, 'inferrepo': False}
         if name not in adefaults:
diff -r fe50341de1ff -r ad1bdea43965 tests/test-alias.t
--- a/tests/test-alias.t	Tue May 03 16:33:25 2016 -0400
+++ b/tests/test-alias.t	Sat May 07 00:16:58 2016 +0100
@@ -525,6 +525,24 @@
   (use "hg help" for the full list of commands or "hg -v" for details)
   [255]
 
+environment variable changes in alias commands
+
+  $ cat > $TESTTMP/setcount.py <<EOF
+  > import os
+  > def uisetup(ui):
+  >     os.environ['COUNT'] = '2'
+  > EOF
+
+  $ cat >> $HGRCPATH <<'EOF'
+  > [extensions]
+  > setcount = $TESTTMP/setcount.py
+  > [alias]
+  > showcount = log -T "$COUNT\n" -r .
+  > EOF
+
+  $ COUNT=1 hg showcount
+  2
+
 This should show id:
 
   $ hg --config alias.log='id' log