[PATCH] broadband-modem, modem-helpers: improve +CGDCONT? error handling

[Ben Chan]

This patch fixes the following crash, which happens when
MMBroadbandBearer tries to parse the NULL response of a failed +CGDCONT?
query. It also fixes a leak in parse_pdp_list where it fails to free the
GError object return by mm_3gpp_parse_cgdcont_read_response.

Thread 0 *CRASHED* ( SIGSEGV @ 0x00000000 )

0x7feb15564c11   [ModemManager]            - mm-modem-helpers.c:850      mm_3gpp_parse_cgdcont_read_response
0x7feb15518e51   [ModemManager]            - mm-broadband-bearer.c:927   parse_pdp_list
0x7feb1551ada2   [ModemManager]            - mm-base-modem-at.c:189      at_sequence_parse_response
0x7feb151d4b86   [libgio-2.0.so.0.3400.3]  - gsimpleasyncresult.c:775    g_simple_async_result_complete
0x7feb1556e223   [ModemManager]            - mm-port-serial-at.c:355     serial_command_ready
0x7feb151d4b86   [libgio-2.0.so.0.3400.3]  - gsimpleasyncresult.c:775    g_simple_async_result_complete
0x7feb1556a834   [ModemManager]            - mm-port-serial.c:141        command_context_complete_and_free
0x7feb1556bc26   [ModemManager]            - mm-port-serial.c:734        port_serial_got_response
0x7feb1556c51a   [ModemManager]            - mm-port-serial.c:758        port_serial_timed_out
0x7feb1508cc33   [libglib-2.0.so.0.3400.3] - gmain.c:4026                g_timeout_dispatch
0x7feb1508c087   [libglib-2.0.so.0.3400.3] - gmain.c:2715                g_main_context_dispatch
0x7feb1508c437   [libglib-2.0.so.0.3400.3] - gmain.c:3290                g_main_context_iterate
0x7feb1508c891   [libglib-2.0.so.0.3400.3] - gmain.c:3484                g_main_loop_run
0x7feb1550ad16   [ModemManager]            - main.c:154                  main
0x7feb14a9e9c6   [libc-2.15.so]            - libc-start.c:234            __libc_start_main
0x7feb1550a808   [ModemManager             + 0x00023808
---
 src/mm-broadband-bearer.c | 14 ++++++++++++--
 src/mm-modem-helpers.c    |  2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/mm-broadband-bearer.c b/src/mm-broadband-bearer.c
index bb2209e..a697e08 100644
--- a/src/mm-broadband-bearer.c
+++ b/src/mm-broadband-bearer.c
@@ -924,10 +924,20 @@ parse_pdp_list (MMBaseModem *modem,
         return FALSE;
     }
 
+    if (error) {
+        mm_dbg ("Unexpected +CGDCONT? error: '%s'", error->message);
+        return FALSE;
+    }
+
     pdp_list = mm_3gpp_parse_cgdcont_read_response (response, &inner_error);
     if (!pdp_list) {
-        /* No predefined PDP contexts found */
-        mm_dbg ("No PDP contexts found");
+        if (inner_error) {
+            mm_dbg ("%s", inner_error->message);
+            g_error_free (inner_error);
+        } else {
+            /* No predefined PDP contexts found */
+            mm_dbg ("No PDP contexts found");
+        }
         return FALSE;
     }
 
diff --git a/src/mm-modem-helpers.c b/src/mm-modem-helpers.c
index 9eefb33..8bdc0e7 100644
--- a/src/mm-modem-helpers.c
+++ b/src/mm-modem-helpers.c
@@ -847,7 +847,7 @@ mm_3gpp_parse_cgdcont_read_response (const gchar *reply,
     GMatchInfo *match_info;
     GList *list;
 
-    if (!reply[0])
+    if (!reply || !reply[0])
         /* No APNs configured, all done */
         return NULL;
 
-- 
1.9.0.279.gdc9e3eb