From 18b8ce249fc7038c9ab739c78053589e1e453233 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?=
 <avarab@gmail.com>
Date: Fri, 17 Feb 2017 11:08:33 +0100
Subject: [PATCH] Add support for specifying --muhome via MU_HOME in the
 environment

When you have multiple mu home directories, e.g. for the use case
detailed in my "Changing mu4e-{maildir,mu-home} from a context hook"
post to the mailing list it's quite inconvenient to have to hammer out
"mu --muhome=.. find .." every time you want to run some ad-hoc
command.

This allows me to set up a screen session where I do searches in mu
directory A in some screen panes, and searches in directory B in
others.

I initially called this MU_MUHOME but then I noticed that the perl
plugin has MUP_MU_HOME for analogous functionality, so I'm just
following its example.

The code I'm adding in mu-util.c is just a copy/paste & adjustment of
the same sort of already tested functionality in
mu_util_guess_maildir() just a few lines earlier.
---
 NEWS.org      |  3 +++
 lib/mu-util.c | 11 +++++++++--
 lib/mu-util.h |  3 ++-
 man/mu.1      |  4 +++-
 man/mug.1     |  4 +++-
 5 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/NEWS.org b/NEWS.org
index 377eb031..5a27fdb9 100644
--- a/NEWS.org
+++ b/NEWS.org
@@ -16,6 +16,9 @@
    - prefer gpg2 for crypto
    - fix a crash when running on OpenBSD
    - fix --clear-links (broken filenames)
+   - You can now set the MU_HOME environment variable as an
+     alternative way of setting the mu homedir via the --muhome
+     commadn-line parameter.
     
 *** mu4e
 
diff --git a/lib/mu-util.c b/lib/mu-util.c
index 367ad78d..cac5a4a9 100644
--- a/lib/mu-util.c
+++ b/lib/mu-util.c
@@ -199,9 +199,16 @@ gchar*
 mu_util_guess_mu_homedir (void)
 {
 	const char* home;
+	const gchar *hdir1;
 
-	/* g_get_home_dir use /etc/passwd, not $HOME; this is better,
-	 * as HOME may be wrong when using 'sudo' etc.*/
+	/* first, try MU_HOME */
+	hdir1 = g_getenv ("MU_HOME");
+
+	if (hdir1 && mu_util_check_dir (hdir1, TRUE, FALSE))
+		return g_strdup (hdir1);
+
+	/* then, g_get_home_dir use /etc/passwd, not $HOME; this is
+	 * better, as HOME may be wrong when using 'sudo' etc.*/
 	home = g_get_home_dir ();
 
 	if (!home) {
diff --git a/lib/mu-util.h b/lib/mu-util.h
index 88afe703..c51f7c6c 100644
--- a/lib/mu-util.h
+++ b/lib/mu-util.h
@@ -62,7 +62,8 @@ char* mu_util_guess_maildir (void)
 
 
 /**
- * guess the place of the mu homedir (typically, ~/.mu). Note, this
+ * guess the place of the mu homedir; first try $MU_HOME; if it is
+ * unset or non-existant, try ~/.mu. Note, the fallback ~/.mu
  * directory does not necessarily exist. mu_util_check_dir can be used
  * to check that
  *
diff --git a/man/mu.1 b/man/mu.1
index 7f2e348a..57c1a644 100644
--- a/man/mu.1
+++ b/man/mu.1
@@ -152,7 +152,9 @@ including \fBmu\fR without any command.
 .TP
 \fB\-\-muhome\fR
 causes \fBmu\fR to use an alternative directory to
-store and read its database and logs. By default, \fI~/.mu\fR is used.
+store and read its database and logs. By default, \fBmu\fR uses
+whatever the \fBMU_HOME\fR environment variable is set to; if it is
+not set, \fI~/.mu\fR is used.
 
 .TP
 \fB\-d\fR, \fB\-\-debug\fR
diff --git a/man/mug.1 b/man/mug.1
index 867daa59..99b29caf 100644
--- a/man/mug.1
+++ b/man/mug.1
@@ -23,7 +23,9 @@ toolbar.
 
 .TP
 \fB\-\-muhome\fR causes \fBmug\fR to use an alternative directory to read its
-database and bookmarks and write its logs. By default, \fI~/.mu\fR is used.
+database and bookmarks and write its logs. By default, \fBmug\fR uses
+whatever the \fBMU_HOME\fR environment variable is set to; if it is
+not set, \fI~/.mu\fR is used.
 
 .SH BUGS
 Please report bugs if you find them: