mu: support MUHOME environment variable

mu/mu-config.cc

@@ -75,8 +75,17 @@ get_output_format(const char* formatstr)
 static void
 set_group_mu_defaults()
 {
-	/* If muhome is not set, we use the XDG Base Directory Specification
-	 * locations. */
+	/* try to determine muhome from command-line or environment;
+	 * note: if not specified, we use XDG defaults */
+
+	if (!MU_CONFIG.muhome) {
+		/* if not set explicity, try the environment */
+		const char* muhome;
+		muhome = g_getenv("MUHOME");
+		if (muhome)
+			MU_CONFIG.muhome = g_strdup(muhome);
+	}
+
 	if (MU_CONFIG.muhome)
 		expand_dir(MU_CONFIG.muhome);
 

mu/tests/test-mu-query.cc

@@ -45,14 +45,16 @@ static std::string
 make_database(const std::string& testdir)
 {
 	char*      tmpdir{test_mu_common_get_random_tmpdir()};
+
+	/* use the env var rather than `--muhome` */
+
+	g_setenv("MUHOME", tmpdir, 1);
 	const auto cmdline{format("/bin/sh -c '"
-				  "%s init  --muhome=%s --maildir=%s --quiet ; "
-				  "%s index --muhome=%s  --quiet'",
+				  "%s init --maildir=%s --quiet ; "
+				  "%s index --quiet'",
 				  MU_PROGRAM,
-				  tmpdir,
 				  testdir.c_str(),
-				  MU_PROGRAM,
-				  tmpdir)};
+				  MU_PROGRAM)};
 
 	if (g_test_verbose())
 		g_printerr("\n%s\n", cmdline.c_str());
@@ -61,6 +63,9 @@ make_database(const std::string& testdir)
 	auto xpath = g_strdup_printf("%s%c%s", tmpdir, G_DIR_SEPARATOR, "xapian");
 	g_free(tmpdir);
 
+	/* ensure MUHOME worked */
+	g_assert_cmpuint(::access(xpath, F_OK), ==, 0);
+
 	std::string dbpath{xpath};
 	g_free(xpath);