From a1f221bd82eb4393ccba83a361b435a4992b532a Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 8 Apr 2016 13:39:17 -0700
Subject: [PATCH] Comint and compile no longer set EMACS
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This mostly restores the change that I reverted on March 23,
fixing most of Bug#20202.  The only part of the change that is
still reverted is the change to M-x term, where compatibility with
current Bash constrains us from moving too quickly (Bug#20484).
Problem reported by Phillip Lord in: http://bugs.gnu.org/20484#108
* 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):
Don’t set EMACS=t in the subsidiary process.
---
 etc/NEWS                  | 6 ++++--
 lisp/comint.el            | 7 -------
 lisp/net/tramp-sh.el      | 1 -
 lisp/progmodes/compile.el | 8 --------
 4 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 95265882ec..78d725bddf 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1398,8 +1398,10 @@ symbol-function was changed not to signal 'void-function' any more.
 *** As a consequence, the second arg of 'indirect-function' is now obsolete.
 
 +++
-** Although comint, term, and compile still set the EMACS variable,
-this is now considered deprecated and will be removed in a future release.
+** M-x shell and M-x compile no longer set the EMACS environment variable.
+This avoids clashing when other programs use the variable for other purposes.
+Although M-x term still sets EMACS for compatibility with Bash 4.3 and earlier,
+this is deprecated and will be phased out when Bash 4.4 or later takes over.
 Use the INSIDE_EMACS environment variable instead.
 
 +++
diff --git a/lisp/comint.el b/lisp/comint.el
index cb79c175f0..dcd4a5ae4c 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -816,13 +816,6 @@ 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 79ff1bea4c..4d529f7aa3 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -520,7 +520,6 @@ 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 0b15a28309..b7ab408f74 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -1702,14 +1702,6 @@ 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)
-- 
2.39.2