Allow users to set location of .xsession-errors

common/configuration.c

@@ -346,6 +346,7 @@ config_init (Configuration *config)
     g_hash_table_insert (config->priv->lightdm_keys, "greeters-directory", GINT_TO_POINTER (KEY_SUPPORTED));
     g_hash_table_insert (config->priv->lightdm_keys, "backup-logs", GINT_TO_POINTER (KEY_SUPPORTED));
     g_hash_table_insert (config->priv->lightdm_keys, "dbus-service", GINT_TO_POINTER (KEY_SUPPORTED));
+    g_hash_table_insert (config->priv->lightdm_keys, "xsession-errors-path", GINT_TO_POINTER (KEY_SUPPORTED));
     g_hash_table_insert (config->priv->lightdm_keys, "logind-load-seats", GINT_TO_POINTER (KEY_DEPRECATED));
 
     g_hash_table_insert (config->priv->seat_keys, "type", GINT_TO_POINTER (KEY_SUPPORTED));

data/lightdm.conf

@@ -17,6 +17,7 @@
 # greeters-directory = Directory to find greeters
 # backup-logs = True to move add a .old suffix to old log files when opening new ones
 # dbus-service = True if LightDM provides a D-Bus service to control it
+# xsession-errors-path = Log file for X session errors, relative to $HOME. Supports environment expansion.
 #
 [LightDM]
 #start-default-seat=true
@@ -35,6 +36,7 @@
 #greeters-directory=$XDG_DATA_DIRS/lightdm/greeters:$XDG_DATA_DIRS/xgreeters
 #backup-logs=true
 #dbus-service=true
+#xsession-errors-path=.xsession-errors
 
 #
 # Seat configuration

src/lightdm.c

@@ -773,6 +773,8 @@ main (int argc, char **argv)
         config_set_boolean (config_get_instance (), "LightDM", "backup-logs", TRUE);
     if (!config_has_key (config_get_instance (), "LightDM", "dbus-service"))
         config_set_boolean (config_get_instance (), "LightDM", "dbus-service", TRUE);
+    if (!config_has_key (config_get_instance (), "LightDM", "xsession-errors-path"))
+        config_set_string (config_get_instance (), "LightDM", "xsession-errors-path", ".xsession-errors");
     if (!config_has_key (config_get_instance (), "Seat:*", "type"))
         config_set_string (config_get_instance (), "Seat:*", "type", "local");
     if (!config_has_key (config_get_instance (), "Seat:*", "pam-service"))

src/session.c

@@ -17,6 +17,7 @@
 #include <unistd.h>
 #include <sys/wait.h>
 #include <fcntl.h>
+#include <glib.h>
 #include <glib/gstdio.h>
 #include <grp.h>
 #include <pwd.h>
@@ -995,12 +996,41 @@ session_get_is_stopping (Session *session)
     return priv->stopping;
 }
 
+static gboolean
+expand_cb (const GMatchInfo *info, GString *result, gpointer data)
+{
+    gchar *match;
+    const gchar *env_text;
+
+    match = g_match_info_fetch (info, 1);
+    env_text = g_getenv (match);
+    if (env_text)
+    {
+        g_string_append (result, env_text);
+    };
+    g_free (match);
+
+    return FALSE;
+}
+
+static gchar *
+expand_environment (const gchar *text)
+{
+    GRegex *pattern;
+    gchar *result;
+
+    pattern = g_regex_new("\\$(?|\\{([a-zA-Z_][a-zA-Z_0-9]*)\\}|([a-zA-Z_][a-zA-Z_0-9]*))", G_REGEX_RAW, G_REGEX_MATCH_DEFAULT, NULL);
+    result = g_regex_replace_eval (pattern, text, -1, 0, 0, expand_cb, NULL, NULL);
+
+    return result;
+}
+
 static void
 session_init (Session *session)
 {
     SessionPrivate *priv = session_get_instance_private (session);
 
-    priv->log_filename = g_strdup (".xsession-errors");
+    priv->log_filename = expand_environment (config_get_string (config_get_instance(), "LightDM", "xsession-errors-path"));
     priv->log_mode = LOG_MODE_BACKUP_AND_TRUNCATE;
     priv->to_child_input = -1;
     priv->from_child_output = -1;