Honor SOURCE_DATE_EPOCH when exporting configuration date.
Autoconf-level patch submitted upstream on Wed Apr 13 17:03:23 UTC 2016

--- a/configure
+++ b/configure
@@ -27737,7 +28573,14 @@
 
 
 ## Configuration date
- CONFIG_DATE="`date`"
+ CONFIG_DATE="`date -u`"
+if test -n "$SOURCE_DATE_EPOCH"; then
+  CONFIG_DATE=`date -u -d "@$SOURCE_DATE_EPOCH" 2>/dev/null \
+               || date -u -r "$SOURCE_DATE_EPOCH" 2>/dev/null`
+  if test -z "$CONFIG_DATE"; then
+    as_fn_error $? "malformed SOURCE_DATE_EPOCH" "$LINENO" 5
+  fi
+fi
 
 ## User doing the configuration
  CONFIG_USER="`whoami`@`hostname`"
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<div class='path'>path: <a href='/guix/log/?id=f5c6e6966c020722700ef0343ab0a6030e2d61b5'>root</a>/<a href='/guix/log/etc?id=f5c6e6966c020722700ef0343ab0a6030e2d61b5'>etc</a>/<a href='/guix/log/etc/indent-code.el?id=f5c6e6966c020722700ef0343ab0a6030e2d61b5'>indent-code.el</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/indent-code.el?id=f5c6e6966c020722700ef0343ab0a6030e2d61b5&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-08-18 23:54:55 +0200'>2020-08-18</span></td><td><a href='/guix/commit/etc/indent-code.el?id=275e66b8b47a6e085a6f359b69af424bc9f6b13d'>etc: indent-code.el: Match not only ‘(define-public’.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/indent-code.el (main): Also match ‘(define’, as intended.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-14 23:05:42 -0400'>2020-05-14</span></td><td><a href='/guix/commit/etc/indent-code.el?id=cb21ae76714f1873d3b3fb40d5135f00ec104b85'>etc: indent-code.el: Use the --quick option.</a><span class='msg-avail'>...<span class='msg-tooltip'>This prevents Emacs from loading the autoload definitions found in its
profile, which needlessly clutters the output.  It also prevents Geiser (if
installed) from blocking the script and asking the user to input the Scheme
implementation to use.

The trick for passing multiple arguments to Emacs is to use what is called a
"sesquicolon" (see https://www.emacswiki.org/emacs/EmacsScripts).

* etc/indent-code.el.in: Rename to...
* etc/indent-code.el: ...this.  Adapt the shebang to use a sesquicolon, and
pass the --quick option to Emacs.  Since this line is interpreted by the
shell, simply use Emacs from the PATH instead of from a hard coded location.
(main): New procedure, used as the entry point.
* configure.ac: Remove the warning about Emacs.  Emacs can now be installed
any time by the user if they want to use the script.
* .gitignore: No longer ignore changes to etc/indent-code.el.
</span></span></td><td>Maxim Cournoyer</td></tr>