modem-helpers: if operator not in UCS2, see if already valid UTF-8

The method doing the operator name normalization takes as input the
current configured modem charset. If this is UCS2, we will now just
assume this is a hint: the string may or may not come in hex/UCS2.

This logic makes the custom operator name loading in Huawei unneeded,
if the modem is configured in UCS2, we still properly process operator
names coming in plain ASCII.

2 files changed, 62 insertions, 9 deletions

diff --git a/src/mm-modem-helpers.c b/src/mm-modem-helpers.c
index fc95e28f..9266a5a0 100644
--- a/src/mm-modem-helpers.c
+++ b/src/mm-modem-helpers.c
@@ -3131,20 +3131,28 @@ mm_3gpp_normalize_operator_name (gchar          **operator,
     if (*operator == NULL)
         return;
 
-    /* Some modems (Option & HSO) return the operator name as a hexadecimal
-     * string of the bytes of the operator name as encoded by the current
-     * character set.
-     */
+    /* Despite +CSCS? may claim supporting UCS2, Some modems (e.g. Huawei)
+     * always report the operator name in ASCII in a +COPS response. */
     if (cur_charset == MM_MODEM_CHARSET_UCS2) {
+        gchar *tmp;
+
+        tmp = g_strdup (*operator);
         /* In this case we're already checking UTF-8 validity */
-        *operator = mm_charset_take_and_convert_to_utf8 (*operator, MM_MODEM_CHARSET_UCS2);
+        tmp = mm_charset_take_and_convert_to_utf8 (tmp, cur_charset);
+        if (tmp) {
+            g_clear_pointer (operator, g_free);
+            *operator = tmp;
+            goto out;
+        }
     }
-    /* Ensure the operator name is valid UTF-8 so that we can send it
-     * through D-Bus and such.
-     */
-    else if (!g_utf8_validate (*operator, -1, NULL))
+
+    /* Charset is unknown or there was an error in conversion; try to see
+     * if the contents we got are valid UTF-8 already. */
+    if (!g_utf8_validate (*operator, -1, NULL))
         g_clear_pointer (operator, g_free);
 
+out:
+
     /* Some modems (Novatel LTE) return the operator name as "Unknown" when
      * it fails to obtain the operator name. Return NULL in such case.
      */
diff --git a/src/tests/test-modem-helpers.c b/src/tests/test-modem-helpers.c
index 1fc8c353..98f30f83 100644
--- a/src/tests/test-modem-helpers.c
+++ b/src/tests/test-modem-helpers.c
@@ -866,6 +866,49 @@ test_cops_query (void)
 }
 
 /*****************************************************************************/
+
+typedef struct {
+    const gchar    *input;
+    MMModemCharset  charset;
+    const gchar    *normalized;
+} NormalizeOperatorTest;
+
+static const NormalizeOperatorTest normalize_operator_tests[] = {
+    /* charset unknown */
+    { "Verizon", MM_MODEM_CHARSET_UNKNOWN, "Verizon" },
+    /* charset configured as IRA (ASCII) */
+    { "Verizon", MM_MODEM_CHARSET_IRA, "Verizon" },
+    /* charset configured as GSM7 */
+    { "Verizon", MM_MODEM_CHARSET_GSM, "Verizon" },
+    /* charset configured as UCS2 */
+    { "0056006500720069007A006F006E", MM_MODEM_CHARSET_UCS2, "Verizon" },
+    { "Verizon",                      MM_MODEM_CHARSET_UCS2, "Verizon" },
+};
+
+static void
+common_test_normalize_operator (const NormalizeOperatorTest *t)
+{
+    gchar *str;
+
+    str = g_strdup (t->input);
+    mm_3gpp_normalize_operator_name (&str, t->charset);
+    if (!t->normalized)
+        g_assert (!str);
+    else
+        g_assert_cmpstr (str, ==, t->normalized);
+    g_free (str);
+}
+
+static void
+test_normalize_operator (void)
+{
+    guint i;
+
+    for (i = 0; i < G_N_ELEMENTS (normalize_operator_tests); i++)
+        common_test_normalize_operator (&normalize_operator_tests[i]);
+}
+
+/*****************************************************************************/
 /* Test CREG/CGREG responses and unsolicited messages */
 
 typedef struct {
@@ -3527,6 +3570,8 @@ int main (int argc, char **argv)
 
     g_test_suite_add (suite, TESTCASE (test_cops_query, NULL));
 
+    g_test_suite_add (suite, TESTCASE (test_normalize_operator, NULL));
+
     g_test_suite_add (suite, TESTCASE (test_creg1_solicited, reg_data));
     g_test_suite_add (suite, TESTCASE (test_creg1_unsolicited, reg_data));
     g_test_suite_add (suite, TESTCASE (test_creg2_mercury_solicited, reg_data));