merge: branch 'jv/strv-checked'

create nm_strvarray_get_idxnull_or_greturn macro, use in libnm api

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1765

src/libnm-core-impl/nm-setting-connection.c

@@ -808,21 +808,11 @@ nm_setting_connection_get_num_secondaries(NMSettingConnection *setting)
 const char *
 nm_setting_connection_get_secondary(NMSettingConnection *setting, guint32 idx)
 {
-    NMSettingConnectionPrivate *priv;
-    guint                       secondaries_len;
-
     g_return_val_if_fail(NM_IS_SETTING_CONNECTION(setting), NULL);
 
-    priv = NM_SETTING_CONNECTION_GET_PRIVATE(setting);
-
-    secondaries_len = nm_g_array_len(priv->secondaries.arr);
-    if (idx >= secondaries_len) {
-        /* access one past the length is OK. */
-        g_return_val_if_fail(idx == secondaries_len, NULL);
-        return NULL;
-    }
-
-    return nm_strvarray_get_idx(priv->secondaries.arr, idx);
+    return nm_strvarray_get_idxnull_or_greturn(
+        NM_SETTING_CONNECTION_GET_PRIVATE(setting)->secondaries.arr,
+        idx);
 }
 
 /**

src/libnm-core-impl/nm-setting-match.c

@@ -68,6 +68,8 @@ nm_setting_match_get_num_interface_names(NMSettingMatch *setting)
  * @setting: the #NMSettingMatch
  * @idx: index number of the DNS search domain to return
  *
+ * Since 1.46, access at index "len" is allowed and returns NULL.
+ *
  * Returns: the interface name at index @idx
  *
  * Since: 1.14
@@ -77,11 +79,7 @@ nm_setting_match_get_interface_name(NMSettingMatch *setting, int idx)
 {
     g_return_val_if_fail(NM_IS_SETTING_MATCH(setting), NULL);
 
-    g_return_val_if_fail(setting->interface_name.arr && idx >= 0
-                             && idx < setting->interface_name.arr->len,
-                         NULL);
-
-    return nm_strvarray_get_idx(setting->interface_name.arr, idx);
+    return nm_strvarray_get_idxnull_or_greturn(setting->interface_name.arr, idx);
 }
 
 /**
@@ -213,6 +211,8 @@ nm_setting_match_get_num_kernel_command_lines(NMSettingMatch *setting)
  * @setting: the #NMSettingMatch
  * @idx: index number of the kernel command line argument to return
  *
+ * Since 1.46, access at index "len" is allowed and returns NULL.
+ *
  * Returns: the kernel command line argument at index @idx
  *
  * Since: 1.26
@@ -222,11 +222,7 @@ nm_setting_match_get_kernel_command_line(NMSettingMatch *setting, guint idx)
 {
     g_return_val_if_fail(NM_IS_SETTING_MATCH(setting), NULL);
 
-    g_return_val_if_fail(setting->kernel_command_line.arr
-                             && idx < setting->kernel_command_line.arr->len,
-                         NULL);
-
-    return nm_strvarray_get_idx(setting->kernel_command_line.arr, idx);
+    return nm_strvarray_get_idxnull_or_greturn(setting->kernel_command_line.arr, idx);
 }
 
 /**
@@ -356,6 +352,8 @@ nm_setting_match_get_num_drivers(NMSettingMatch *setting)
  * @setting: the #NMSettingMatch
  * @idx: index number of the DNS search domain to return
  *
+ * Since 1.46, access at index "len" is allowed and returns NULL.
+ *
  * Returns: the driver at index @idx
  *
  * Since: 1.26
@@ -365,9 +363,7 @@ nm_setting_match_get_driver(NMSettingMatch *setting, guint idx)
 {
     g_return_val_if_fail(NM_IS_SETTING_MATCH(setting), NULL);
 
-    g_return_val_if_fail(setting->driver.arr && idx < setting->driver.arr->len, NULL);
-
-    return nm_strvarray_get_idx(setting->driver.arr, idx);
+    return nm_strvarray_get_idxnull_or_greturn(setting->driver.arr, idx);
 }
 
 /**
@@ -495,6 +491,8 @@ nm_setting_match_get_num_paths(NMSettingMatch *setting)
  * @setting: the #NMSettingMatch
  * @idx: index number of the path to return
  *
+ * Since 1.46, access at index "len" is allowed and returns NULL.
+ *
  * Returns: the path at index @idx
  *
  * Since: 1.26
@@ -504,9 +502,7 @@ nm_setting_match_get_path(NMSettingMatch *setting, guint idx)
 {
     g_return_val_if_fail(NM_IS_SETTING_MATCH(setting), NULL);
 
-    g_return_val_if_fail(setting->path.arr && idx < setting->path.arr->len, NULL);
-
-    return nm_strvarray_get_idx(setting->path.arr, idx);
+    return nm_strvarray_get_idxnull_or_greturn(setting->path.arr, idx);
 }
 
 /**

src/libnm-glib-aux/nm-shared-utils.h

@@ -3019,6 +3019,20 @@ nm_strvarray_get_idx(GArray *array, guint idx)
     return nm_g_array_index(array, const char *, idx);
 }
 
+/* nm_strvarray_get_idxnull_or_greturn() permits access at `len`,
+ * returning NULL. If the access is out of bounds, the assertion
+ * will fail (and also return NULL). */
+#define nm_strvarray_get_idxnull_or_greturn(arr, idx)           \
+    ({                                                          \
+        GArray *_arr = (arr);                                   \
+        gsize   _idx = (idx);                                   \
+        guint   _len = nm_g_array_len(_arr);                    \
+                                                                \
+        g_return_val_if_fail(_idx <= _len, NULL);               \
+                                                                \
+        _idx == _len ? NULL : nm_strvarray_get_idx(_arr, _idx); \
+    })
+
 static inline const char *const *
 nm_strvarray_get_strv_non_empty(GArray *arr, guint *length)
 {