Ignore slot sync for slots > 256

Clang doesn't support variable length arrays inside a struct so we could
either make our life complicated or just assume no-one is using more than 256
slots and hard-code that. Let's go for the easy solution until someone
notices.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
index 98645bb17c125434c7cd8d05be75d3bebca5f466..bd6fc96acf7daeab27eecd1330c15ed0a4dcf7cc 100644 (file)
--- a/libevdev/libevdev.c
+++ b/libevdev/libevdev.c
@@ -677,16 +677,15 @@ static int
 sync_mt_state(struct libevdev *dev,
              struct slot_change_state changes_out[dev->num_slots])
 {
+#define MAX_SLOTS 256
        int rc;
-       struct slot_change_state changes[dev->num_slots];
-
-       memset(changes, 0, sizeof(changes));
+       struct slot_change_state changes[MAX_SLOTS] = {0};
 
        for (int axis = ABS_MT_MIN; axis <= ABS_MT_MAX; axis++) {
                /* EVIOCGMTSLOTS required format */
                struct mt_sync_state {
                        uint32_t code;
-                       int32_t val[dev->num_slots];
+                       int32_t val[MAX_SLOTS];
                } mt_state;
 
                if (axis == ABS_MT_SLOT ||
@@ -698,7 +697,7 @@ sync_mt_state(struct libevdev *dev,
                if (rc < 0)
                        goto out;
 
-               for (int slot = 0; slot < dev->num_slots; slot++) {
+               for (int slot = 0; slot < min(MAX_SLOTS, dev->num_slots); slot++) {
                        int val_before = *slot_value(dev, slot, axis),
                            val_after = mt_state.val[slot];
 
@@ -729,7 +728,7 @@ sync_mt_state(struct libevdev *dev,
                }
        }
 
-       memcpy(changes_out, changes, sizeof(changes));
+       memcpy(changes_out, changes, sizeof(*changes) * dev->num_slots);
 out:
        return rc;
 }