diff --git a/kitty/child-monitor.c b/kitty/child-monitor.c
index 2c0463d8a..b3e03efa8 100644
--- a/kitty/child-monitor.c
+++ b/kitty/child-monitor.c
@@ -1343,13 +1343,13 @@ read_bytes(int fd, Screen *screen) {
         if (len < 0) {
             if (errno == EINTR || errno == EAGAIN) continue;
             if (errno != EIO) perror("Call to read() from child fd failed");
+            vt_parser_commit_write(screen->vt_parser, 0);
             return false;
         }
         break;
     }
     vt_parser_commit_write(screen->vt_parser, len);
-    if (UNLIKELY(len == 0)) return false;
-    return true;
+    return len != 0;
 }
 
 
diff --git a/kitty/vt-parser.c b/kitty/vt-parser.c
index f1b814336..eadd2713e 100644
--- a/kitty/vt-parser.c
+++ b/kitty/vt-parser.c
@@ -1581,6 +1581,7 @@ vt_parser_create_write_buffer(Parser *p, size_t *sz) {
     PS *self = (PS*)p->state;
     uint8_t *ans;
     with_lock {
+        if (self->write.sz) fatal("vt_parser_create_write_buffer() called with an already existing write buffer");
         *sz = BUF_SZ - self->read.sz;
         self->write.offset = self->read.sz;
         self->write.sz = *sz;