bug#5456: vc-hg-state does not search hg in vc-path

[Stephan Bergmann]

At least in 23.1, vc-hg-state (and vc-hg-working-revision) in vc-hg.el call 
"hg" without making sure that it is being searched for in vc-path (as is done 
in vc-dispatcher.el by extending exec-path).  What fixed it for me (on recent 
trunk) is

---8<---
=== modified file 'lisp/vc-hg.el'
--- lisp/vc-hg.el       2010-01-13 08:35:10 +0000
+++ lisp/vc-hg.el       2010-01-22 21:46:14 +0000
@@ -169,7 +169,8 @@
                       ;; Ignore all errors.
                      (let ((process-environment
                             ;; Avoid localization of messages so we can parse 
the output.
-                            (append (list "TERM=dumb" "LANGUAGE=C" "HGRC=") 
process-environment)))
+                            (append (list "TERM=dumb" "LANGUAGE=C" "HGRC=") 
process-environment))
+                            (exec-path (append vc-path exec-path)))
 
                      (process-file
                        "hg" nil t nil
@@ -205,7 +206,8 @@
                      (let ((process-environment
                             ;; Avoid localization of messages so we can parse 
the output.
                             (append (list "TERM=dumb" "LANGUAGE=C" "HGRC=")
-                                    process-environment)))
+                                    process-environment))
+                            (exec-path (append vc-path exec-path)))
                        ;; Ignore all errors.
                        (process-file
                         "hg" nil t nil

---8<---

-Stephan