serial: report port-not-open in queueing commands via callback

Reporting errors instead of just returning permits routines like
mm-generic-gsm.c:simple_get_status() to work again, as their callbacks
get the error they are expecting. To make this work, adapt get_csq_done()
to handle a NULL response when error is set, and make sure that multiple
errors don't step on each other in the mm_callback_info_chain() sequence
created by simple_get_status().

Change-Id: Ie3a72b1ce71b7f117e8b1f3da7a406c4d2da9e02

2 files changed, 20 insertions, 4 deletions

diff --git a/src/mm-generic-gsm.c b/src/mm-generic-gsm.c
index 2604b09f..b6d56616 100644
--- a/src/mm-generic-gsm.c
+++ b/src/mm-generic-gsm.c
@@ -4226,7 +4226,7 @@ get_csq_done (MMAtSerialPort *port,
               gpointer user_data)
 {
     MMCallbackInfo *info = (MMCallbackInfo *) user_data;
-    char *reply = response->str;
+    char *reply;
     gboolean parsed = FALSE;
 
     /* If the modem has already been removed, return without
@@ -4239,6 +4239,7 @@ get_csq_done (MMAtSerialPort *port,
         goto done;
     }
 
+    reply = response->str;
     if (!strncmp (reply, "+CSQ: ", 6)) {
         /* Got valid reply */
         int quality;
@@ -5756,6 +5757,9 @@ simple_status_got_signal_quality (MMModem *modem,
     if (!error) {
         properties = (GHashTable *) mm_callback_info_get_data (info, SS_HASH_TAG);
         g_hash_table_insert (properties, "signal_quality", simple_uint_value (result));
+    } else {
+        g_clear_error (&info->error);
+        info->error = g_error_copy (error);
     }
     mm_callback_info_chain_complete_one (info);
 }
@@ -5772,6 +5776,9 @@ simple_status_got_band (MMModem *modem,
     if (!error) {
         properties = (GHashTable *) mm_callback_info_get_data (info, SS_HASH_TAG);
         g_hash_table_insert (properties, "band", simple_uint_value (result));
+    } else {
+        g_clear_error (&info->error);
+        info->error = g_error_copy (error);
     }
     mm_callback_info_chain_complete_one (info);
 }
@@ -5791,9 +5798,10 @@ simple_status_got_reg_info (MMModemGsmNetwork *modem,
     if (!modem || mm_callback_info_check_modem_removed (info))
         return;
 
-    if (error)
+    if (error) {
+        g_clear_error (&info->error);
         info->error = g_error_copy (error);
-    else {
+    } else {
         properties = (GHashTable *) mm_callback_info_get_data (info, SS_HASH_TAG);
 
         g_hash_table_insert (properties, "registration_status", simple_uint_value (status));
diff --git a/src/mm-serial-port.c b/src/mm-serial-port.c
index 29f99ef3..ab64dc80 100644
--- a/src/mm-serial-port.c
+++ b/src/mm-serial-port.c
@@ -1021,9 +1021,17 @@ internal_queue_command (MMSerialPort *self,
     MMQueueData *info;
 
     g_return_if_fail (MM_IS_SERIAL_PORT (self));
-    g_return_if_fail (priv->open_count > 0);
     g_return_if_fail (command != NULL);
 
+    if (priv->open_count == 0) {
+        GError *error = g_error_new_literal (MM_SERIAL_ERROR,
+                                             MM_SERIAL_ERROR_SEND_FAILED,
+                                             "Sending command failed: device is not enabled");
+        callback (self, NULL, error, user_data);
+        g_error_free (error);
+        return;
+    }
+
     info = g_slice_new0 (MMQueueData);
     if (take_command)
         info->command = command;