From: Paul Eggert <eggert@penguin.cs.ucla.edu>
Date: Wed, 23 Mar 2016 22:07:56 +0000 (-0700)
Subject: Comint, term, and compile now set EMACS
X-Git-Tag: emacs-25.0.93~89^2~29
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=73d213f;p=emacs.git

Comint, term, and compile now set EMACS

This fixes directory tracking in ansi-term, at the expense of
breaking some usages of 'configure'.  Setting EMACS is meant to be
a somewhat temporary measure, until Bash 4.4 comes out and is
common.  (Bug#20484).
* etc/NEWS: Document this.
* lisp/comint.el (comint-exec-1):
* lisp/net/tramp-sh.el (tramp-remote-process-environment):
* lisp/progmodes/compile.el (compilation-start):
* lisp/term.el (term-exec-1):
Go back to setting the EMACS environment variable, for backward
compatibility to Bash 4.3 and earlier.
---

diff --git a/etc/NEWS b/etc/NEWS
index 8ce194a69ca..f952a14b1ec 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1404,7 +1404,8 @@ symbol-function was changed not to signal 'void-function' any more.
 *** As a consequence, the second arg of 'indirect-function' is now obsolete.
 
 +++
-** Comint, term, and compile do not set the EMACS env var any more.
+** Although comint, term, and compile still set the EMACS variable,
+this is now considered deprecated and will be removed in a future release.
 Use the INSIDE_EMACS environment variable instead.
 
 +++
diff --git a/lisp/comint.el b/lisp/comint.el
index dcd4a5ae4cf..cb79c175f0e 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -816,6 +816,13 @@ series of processes in the same Comint buffer.  The hook
 		    (format "COLUMNS=%d" (window-width)))
 	    (list "TERM=emacs"
 		  (format "TERMCAP=emacs:co#%d:tc=unknown:" (window-width))))
+
+	  ;; This hack is for backward compatibility with Bash 4.3 and
+	  ;; earlier.  It can break common uses of 'configure', so
+	  ;; remove it once Bash 4.4 or later is common.
+	  (unless (getenv "EMACS")
+	    (list "EMACS=t"))
+
 	  (list (format "INSIDE_EMACS=%s,comint" emacs-version))
 	  process-environment))
 	(default-directory
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 1f43747c094..9fa46109a5a 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -520,6 +520,7 @@ as given in your `~/.profile'."
 (defcustom tramp-remote-process-environment
   `("TMOUT=0" "LC_CTYPE=''"
     ,(format "TERM=%s" tramp-terminal-type)
+    "EMACS=t" ;; Deprecated; remove this line once Bash 4.4-or-later is common.
     ,(format "INSIDE_EMACS='%s,tramp:%s'" emacs-version tramp-version)
     "CDPATH=" "HISTORY=" "MAIL=" "MAILCHECK=" "MAILPATH=" "PAGER=cat"
     "autocorrect=" "correct=")
diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index b7ab408f744..0b15a283090 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -1702,6 +1702,14 @@ Returns the compilation buffer created."
 		(list "TERM=emacs"
 		      (format "TERMCAP=emacs:co#%d:tc=unknown:"
 			      (window-width))))
+
+	      ;; Set the EMACS variable, but
+	      ;; don't override users' setting of $EMACS.
+	      ;; Remove this hack once Bash 4.4-or-later is common,
+	      ;; since it can break 'configure'.
+	      (unless (getenv "EMACS")
+		(list "EMACS=t"))
+
 	      (list (format "INSIDE_EMACS=%s,compile" emacs-version))
 	      (copy-sequence process-environment))))
 	(set (make-local-variable 'compilation-arguments)
diff --git a/lisp/term.el b/lisp/term.el
index a2e01ed4a29..6fd3a5e6261 100644
--- a/lisp/term.el
+++ b/lisp/term.el
@@ -1454,6 +1454,13 @@ Using \"emacs\" loses, because bash disables editing if $TERM == emacs.")
 	   (format "TERMINFO=%s" data-directory)
 	   (format term-termcap-format "TERMCAP="
 		   term-term-name term-height term-width)
+
+	   ;; This is for backwards compatibility with Bash 4.3 and earlier.
+	   ;; Remove this hack once Bash 4.4-or-later is common, because
+	   ;; it breaks './configure' of some packages that expect it to
+	   ;; say where to find EMACS.
+	   (format "EMACS=%s (term:%s)" emacs-version term-protocol-version)
+
 	   (format "INSIDE_EMACS=%s,term:%s" emacs-version term-protocol-version)
 	   (format "LINES=%d" term-height)
 	   (format "COLUMNS=%d" term-width))