Don't progress transaction queue if any are partially complete

This fixes an issue where views might commit to a transaction ahead of
the first one, and applying the first transaction causes us to save a
buffer of the wrong size.

1 files changed, 12 insertions, 0 deletions

diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
index 4e6af86a..edbe34e5 100644
--- a/sway/desktop/transaction.c
+++ b/sway/desktop/transaction.c
@@ -213,6 +213,18 @@ static void transaction_apply(struct sway_transaction *transaction) {
 }
 
 static void transaction_progress_queue() {
+        // Check if any transactions in the queue are in a partially ready state.
+        // If so, we shouldn't progress any transactions, even ones which are fully
+        // ready at the front of the queue, because the views in the ready
+        // transactions might have committed past it to a transaction which isn't
+        // yet ready.
+        for (int i = 0; i < server.transactions->length; ++i) {
+                struct sway_transaction *transaction = server.transactions->items[i];
+                if (transaction->num_waiting != 0 &&
+                                transaction->num_waiting != transaction->num_configures) {
+                        return;
+                }
+        }
         while (server.transactions->length) {
                 struct sway_transaction *transaction = server.transactions->items[0];
                 if (transaction->num_waiting) {