ui/gtk: vte: fix sending multiple characeters

When using the GTK UI with libvte, multicharacter keystrokes are not
sent correctly (such as arrow keys). gd_vc_in should check the
CharBackend's can_receive instead of assuming multiple characters can be
received. This is not an issue for e.g. the SDL UI because
qemu_chr_be_write is called with len=1 for each character (SDL sends
more than once keystroke).

Modify gd_vc_in to call qemu_chr_be_write multiple times if necessary.

Buglink: https://bugs.launchpad.net/qemu/+bug/1407808

Signed-off-by: Zack Marvel <zpmarvel@gmail.com>
Message-Id: <20210221170613.13183-2-zpmarvel@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/ui/gtk.c b/ui/gtk.c
index 79dc240120..bad716f136 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1786,7 +1786,16 @@ static gboolean gd_vc_in(VteTerminal *terminal, gchar *text, guint size,
         }
     }
 
-    qemu_chr_be_write(vc->vte.chr, (uint8_t  *)text, (unsigned int)size);
+    int remaining = size;
+    uint8_t* p = (uint8_t *)text;
+    while (remaining > 0) {
+        int can_write = qemu_chr_be_can_write(vc->vte.chr);
+        int written = MIN(remaining, can_write);
+        qemu_chr_be_write(vc->vte.chr, p, written);
+
+        remaining -= written;
+        p += written;
+    }
     return TRUE;
 }