diff tests/test-chg.t @ 50353:c2a1f8668606 stable

chg: set CHGHG before connecting to command server

cf4d2f31 (!523) changed chg to set `CHGHG` itself when spawning a new command
server, in order to ensure that the path to the `hg` executable would be checked
during server validation. (This is useful when chg is built with `HGPATHREL`).

However, that change broke chg because it failed to set `CHGHG` before trying
to connect to an existing command server. This means that if `CHGHG` is not
present in the environment, chg will always spawn a new command server, entirely
negating the point of chg.

This breakage wasn't initially caught because of the difficulty of writing
automated tests with the `HGPATHREL` feature enabled, which meant the change
was only tested manually to make sure that it fixed the problem with `HGPATHREL`
that prompted the change.

In practice, this functionality is only really useful when chg is built with
`HGPATHREL`, so I considered wrapping it in an `#ifdef` to preserve the old
behavior by default. However, this makes it hard to write tests since one would
have to explicitly set `HGPATHREL=1` when running `run-tests.py` (which is why
the original change lacked tests). It would be great if there were a way of
testing features that are gated behind conditional compilation.

--- a/tests/test-chg.t	Mon Apr 24 10:30:08 2023 -0400
+++ b/tests/test-chg.t	Thu Apr 20 09:23:58 2023 -0400
@@ -553,3 +553,20 @@
   $ filteredchg log -r . --no-profile
   $ filteredchg log -r .
   Sample count: * (glob)
+
+chg setting CHGHG itself
+------------------------
+
+If CHGHG is not set, chg will set it before spawning the command server.
+  $ hg --kill-chg-daemon
+  $ HG=$CHGHG CHGHG= CHGDEBUG= hg debugshell -c \
+  >   'ui.write(b"CHGHG=%s\n" % ui.environ.get(b"CHGHG"))' 2>&1 \
+  >   | egrep 'CHGHG|start'
+  chg: debug: * start cmdserver at * (glob)
+  CHGHG=/*/install/bin/hg (glob)
+
+Running the same command a second time shouldn't spawn a new command server.
+  $ HG=$CHGHG CHGHG= CHGDEBUG= hg debugshell -c \
+  >   'ui.write(b"CHGHG=%s\n" % ui.environ.get(b"CHGHG"))' 2>&1 \
+  >   | egrep 'CHGHG|start'
+  CHGHG=/*/install/bin/hg (glob)