lib/open: support XDG_DATA_HOME as a fallback database location.

This changes some error reporting, either intentionally by reporting
the highest level missing directory, or by side effect from looking in
XDG locations when given null database location.

lib/open.cc

@@ -181,6 +181,7 @@ _choose_database_path (void *ctx,
 		       const char *profile,
 		       GKeyFile **key_file,
 		       const char **database_path,
+		       bool *split,
 		       char **message)
 {
     notmuch_status_t status;
@@ -203,6 +204,11 @@ _choose_database_path (void *ctx,
 	}
     }
 
+    if (! *database_path) {
+	*database_path = _xdg_dir (ctx, "XDG_DATA_HOME", ".local/share", profile);
+	*split = true;
+    }
+
     if (*database_path == NULL) {
 	*message = strdup ("Error: Cannot open a database for a NULL path.\n");
 	return NOTMUCH_STATUS_NULL_POINTER;
@@ -462,6 +468,7 @@ notmuch_database_open_with_config (const char *database_path,
     notmuch_database_t *notmuch = NULL;
     char *message = NULL;
     GKeyFile *key_file = NULL;
+    bool split = false;
 
     _init_libs ();
 
@@ -471,7 +478,8 @@ notmuch_database_open_with_config (const char *database_path,
 	goto DONE;
     }
 
-    if ((status = _choose_database_path (local, config_path, profile, &key_file, &database_path,
+    if ((status = _choose_database_path (local, config_path, profile,
+					 &key_file, &database_path, &split,
 					 &message)))
 	goto DONE;
 
@@ -563,7 +571,8 @@ notmuch_database_create_with_config (const char *database_path,
     _init_libs ();
 
     if ((status = _choose_database_path (local, config_path, profile,
-					 &key_file, &database_path, &message)))
+					 &key_file, &database_path, &split,
+					 &message)))
 	goto DONE;
 
     status = _db_dir_exists (database_path, &message);

test/T055-path-config.sh

@@ -37,8 +37,31 @@ symlink_config () {
     unset DATABASE_PATH
 }
 
-for config in traditional split symlink; do
-    # start each set of tests with a known set of messages
+xdg_config () {
+    local dir
+    local profile=${1:-default}
+
+    if [[ $profile != default ]]; then
+	export NOTMUCH_PROFILE=$profile
+    fi
+
+    backup_config
+    DATABASE_PATH="${HOME}/.local/share/notmuch/${profile}"
+    rm -rf $DATABASE_PATH
+    mkdir -p $DATABASE_PATH
+
+    config_dir="${HOME}/.config/notmuch/${profile}"
+    mkdir -p ${config_dir}
+    CONFIG_PATH=$config_dir/config
+    mv ${NOTMUCH_CONFIG} $CONFIG_PATH
+    unset NOTMUCH_CONFIG
+
+    notmuch --config=${CONFIG_PATH} config set database.mail_root ${TMP_DIRECTORY}/mail
+    notmuch --config=${CONFIG_PATH} config set database.path
+}
+
+for config in traditional split XDG XDG+profile symlink; do
+    #start each set of tests with an known set of messages
     add_email_corpus
 
     case $config in
@@ -49,6 +72,14 @@ for config in traditional split symlink; do
 	    split_config
 	    mv mail/.notmuch/xapian $DATABASE_PATH
 	    ;;
+	XDG)
+	    xdg_config
+	    mv mail/.notmuch/xapian $DATABASE_PATH
+	    ;;
+	XDG+profile)
+	    xdg_config ${RANDOM}
+	    mv mail/.notmuch/xapian $DATABASE_PATH
+	    ;;
 	symlink)
 	    symlink_config
 	    ;;

test/T560-lib-error.sh

@@ -22,7 +22,7 @@ EOF
 cat <<'EOF' >EXPECTED
 == stdout ==
 == stderr ==
-Error: Cannot open a database for a NULL path.
+Error: Cannot open database at CWD/home/.local/share/notmuch/default: No such file or directory.
 EOF
 test_expect_equal_file EXPECTED OUTPUT
 
@@ -93,7 +93,7 @@ EOF
 cat <<'EOF' >EXPECTED
 == stdout ==
 == stderr ==
-Error: Cannot open a database for a NULL path.
+Error: Cannot open database at CWD/home/.local/share/notmuch/default: No such file or directory.
 EOF
 test_expect_equal_file EXPECTED OUTPUT
 

test/T590-libconfig.sh

@@ -519,8 +519,8 @@ cat <<'EOF' >EXPECTED
 == stdout ==
 == stderr ==
 error opening database
-Erroneous NULL pointer
-Error: Cannot open a database for a NULL path.
+Something went wrong trying to read or write a file
+Error: Cannot open database at CWD/home/.local/share/notmuch/default: No such file or directory.
 
 EOF
 test_expect_equal_file EXPECTED OUTPUT