diff --git a/audio/mixeng.c b/audio/mixeng.c
index f27deb165b..100a306d6f 100644
--- a/audio/mixeng.c
+++ b/audio/mixeng.c
@@ -342,13 +342,13 @@ f_sample *mixeng_clip_float[2] = {
 void audio_sample_to_uint64(const void *samples, int pos,
                             uint64_t *left, uint64_t *right)
 {
-    const struct st_sample *sample = samples;
-    sample += pos;
 #ifdef FLOAT_MIXENG
     error_report(
         "Coreaudio and floating point samples are not supported by replay yet");
     abort();
 #else
+    const struct st_sample *sample = samples;
+    sample += pos;
     *left = sample->l;
     *right = sample->r;
 #endif
@@ -357,13 +357,13 @@ void audio_sample_to_uint64(const void *samples, int pos,
 void audio_sample_from_uint64(void *samples, int pos,
                             uint64_t left, uint64_t right)
 {
-    struct st_sample *sample = samples;
-    sample += pos;
 #ifdef FLOAT_MIXENG
     error_report(
         "Coreaudio and floating point samples are not supported by replay yet");
     abort();
 #else
+    struct st_sample *sample = samples;
+    sample += pos;
     sample->l = left;
     sample->r = right;
 #endif
diff --git a/hw/display/ati.c b/hw/display/ati.c
index 31f22754dc..6e38e00502 100644
--- a/hw/display/ati.c
+++ b/hw/display/ati.c
@@ -955,7 +955,9 @@ static void ati_vga_realize(PCIDevice *dev, Error **errp)
     }
 
     /* init vga bits */
-    vga_common_init(vga, OBJECT(s));
+    if (!vga_common_init(vga, OBJECT(s), errp)) {
+        return;
+    }
     vga_init(vga, OBJECT(s), pci_address_space(dev),
              pci_address_space_io(dev), true);
     vga->con = graphic_console_init(DEVICE(s), 0, s->vga.hw_ops, &s->vga);
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index fdca6ca659..3bb6a58698 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -2940,27 +2940,30 @@ void cirrus_init_common(CirrusVGAState *s, Object *owner,
 
 static void pci_cirrus_vga_realize(PCIDevice *dev, Error **errp)
 {
-     PCICirrusVGAState *d = PCI_CIRRUS_VGA(dev);
-     CirrusVGAState *s = &d->cirrus_vga;
-     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
-     int16_t device_id = pc->device_id;
+    PCICirrusVGAState *d = PCI_CIRRUS_VGA(dev);
+    CirrusVGAState *s = &d->cirrus_vga;
+    PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
+    int16_t device_id = pc->device_id;
 
-     /* follow real hardware, cirrus card emulated has 4 MB video memory.
-       Also accept 8 MB/16 MB for backward compatibility. */
-     if (s->vga.vram_size_mb != 4 && s->vga.vram_size_mb != 8 &&
-         s->vga.vram_size_mb != 16) {
-         error_setg(errp, "Invalid cirrus_vga ram size '%u'",
-                    s->vga.vram_size_mb);
-         return;
-     }
-     /* setup VGA */
-     vga_common_init(&s->vga, OBJECT(dev));
-     cirrus_init_common(s, OBJECT(dev), device_id, 1, pci_address_space(dev),
-                        pci_address_space_io(dev));
-     s->vga.con = graphic_console_init(DEVICE(dev), 0, s->vga.hw_ops, &s->vga);
-
-     /* setup PCI */
+    /*
+     * Follow real hardware, cirrus card emulated has 4 MB video memory.
+     * Also accept 8 MB/16 MB for backward compatibility.
+     */
+    if (s->vga.vram_size_mb != 4 && s->vga.vram_size_mb != 8 &&
+        s->vga.vram_size_mb != 16) {
+        error_setg(errp, "Invalid cirrus_vga ram size '%u'",
+                   s->vga.vram_size_mb);
+        return;
+    }
+    /* setup VGA */
+    if (!vga_common_init(&s->vga, OBJECT(dev), errp)) {
+        return;
+    }
+    cirrus_init_common(s, OBJECT(dev), device_id, 1, pci_address_space(dev),
+                       pci_address_space_io(dev));
+    s->vga.con = graphic_console_init(DEVICE(dev), 0, s->vga.hw_ops, &s->vga);
 
+    /* setup PCI */
     memory_region_init(&s->pci_bar, OBJECT(dev), "cirrus-pci-bar0", 0x2000000);
 
     /* XXX: add byte swapping apertures */
@@ -2968,14 +2971,14 @@ static void pci_cirrus_vga_realize(PCIDevice *dev, Error **errp)
     memory_region_add_subregion(&s->pci_bar, 0x1000000,
                                 &s->cirrus_linear_bitblt_io);
 
-     /* setup memory space */
-     /* memory #0 LFB */
-     /* memory #1 memory-mapped I/O */
-     /* XXX: s->vga.vram_size must be a power of two */
-     pci_register_bar(&d->dev, 0, PCI_BASE_ADDRESS_MEM_PREFETCH, &s->pci_bar);
-     if (device_id == CIRRUS_ID_CLGD5446) {
-         pci_register_bar(&d->dev, 1, 0, &s->cirrus_mmio_io);
-     }
+    /* setup memory space */
+    /* memory #0 LFB */
+    /* memory #1 memory-mapped I/O */
+    /* XXX: s->vga.vram_size must be a power of two */
+    pci_register_bar(&d->dev, 0, PCI_BASE_ADDRESS_MEM_PREFETCH, &s->pci_bar);
+    if (device_id == CIRRUS_ID_CLGD5446) {
+        pci_register_bar(&d->dev, 1, 0, &s->cirrus_mmio_io);
+    }
 }
 
 static Property pci_vga_cirrus_properties[] = {
diff --git a/hw/display/cirrus_vga_isa.c b/hw/display/cirrus_vga_isa.c
index 4f6fb1af3b..96144bd690 100644
--- a/hw/display/cirrus_vga_isa.c
+++ b/hw/display/cirrus_vga_isa.c
@@ -56,7 +56,9 @@ static void isa_cirrus_vga_realizefn(DeviceState *dev, Error **errp)
         return;
     }
     s->global_vmstate = true;
-    vga_common_init(s, OBJECT(dev));
+    if (!vga_common_init(s, OBJECT(dev), errp)) {
+        return;
+    }
     cirrus_init_common(&d->cirrus_vga, OBJECT(dev), CIRRUS_ID_CLGD5430, 0,
                        isa_address_space(isadev),
                        isa_address_space_io(isadev));
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 1f9ad31943..adbdbcaeb6 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -2215,7 +2215,11 @@ static void qxl_realize_primary(PCIDevice *dev, Error **errp)
     qxl_init_ramsize(qxl);
     vga->vbe_size = qxl->vgamem_size;
     vga->vram_size_mb = qxl->vga.vram_size / MiB;
-    vga_common_init(vga, OBJECT(dev));
+    vga_common_init(vga, OBJECT(dev), &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
     vga_init(vga, OBJECT(dev),
              pci_address_space(dev), pci_address_space_io(dev), false);
     portio_list_init(&qxl->vga_port_list, OBJECT(dev), qxl_vga_portio_list,
diff --git a/hw/display/vga-isa.c b/hw/display/vga-isa.c
index 90851e730b..46abbc5653 100644
--- a/hw/display/vga-isa.c
+++ b/hw/display/vga-isa.c
@@ -62,7 +62,10 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp)
     const MemoryRegionPortio *vga_ports, *vbe_ports;
 
     s->global_vmstate = true;
-    vga_common_init(s, OBJECT(dev));
+    if (!vga_common_init(s, OBJECT(dev), errp)) {
+        return;
+    }
+
     s->legacy_address_space = isa_address_space(isadev);
     vga_io_memory = vga_init_io(s, OBJECT(dev), &vga_ports, &vbe_ports);
     isa_register_portio_list(isadev, &d->portio_vga,
diff --git a/hw/display/vga-mmio.c b/hw/display/vga-mmio.c
index 4969368081..75dfcedea5 100644
--- a/hw/display/vga-mmio.c
+++ b/hw/display/vga-mmio.c
@@ -102,7 +102,10 @@ static void vga_mmio_realizefn(DeviceState *dev, Error **errp)
 
     s->vga.bank_offset = 0;
     s->vga.global_vmstate = true;
-    vga_common_init(&s->vga, OBJECT(dev));
+    if (!vga_common_init(&s->vga, OBJECT(dev), errp)) {
+        return;
+    }
+
     sysbus_init_mmio(sbd, &s->vga.vram);
     s->vga.con = graphic_console_init(dev, 0, s->vga.hw_ops, &s->vga);
 }
diff --git a/hw/display/vga-pci.c b/hw/display/vga-pci.c
index 62fb5c38c1..3e5bc259f7 100644
--- a/hw/display/vga-pci.c
+++ b/hw/display/vga-pci.c
@@ -239,7 +239,9 @@ static void pci_std_vga_realize(PCIDevice *dev, Error **errp)
     bool edid = false;
 
     /* vga + console init */
-    vga_common_init(s, OBJECT(dev));
+    if (!vga_common_init(s, OBJECT(dev), errp)) {
+        return;
+    }
     vga_init(s, OBJECT(dev), pci_address_space(dev), pci_address_space_io(dev),
              true);
 
@@ -275,7 +277,9 @@ static void pci_secondary_vga_realize(PCIDevice *dev, Error **errp)
     bool edid = false;
 
     /* vga + console init */
-    vga_common_init(s, OBJECT(dev));
+    if (!vga_common_init(s, OBJECT(dev), errp)) {
+        return;
+    }
     s->con = graphic_console_init(DEVICE(dev), 0, s->hw_ops, s);
 
     /* mmio bar */
diff --git a/hw/display/vga.c b/hw/display/vga.c
index 9d1f66af40..a7a291fa20 100644
--- a/hw/display/vga.c
+++ b/hw/display/vga.c
@@ -2168,9 +2168,10 @@ static inline uint32_t uint_clamp(uint32_t val, uint32_t vmin, uint32_t vmax)
     return val;
 }
 
-void vga_common_init(VGACommonState *s, Object *obj)
+bool vga_common_init(VGACommonState *s, Object *obj, Error **errp)
 {
     int i, j, v, b;
+    Error *local_err = NULL;
 
     for(i = 0;i < 256; i++) {
         v = 0;
@@ -2205,8 +2206,18 @@ void vga_common_init(VGACommonState *s, Object *obj)
     s->vbe_size_mask = s->vbe_size - 1;
 
     s->is_vbe_vmstate = 1;
+
+    if (s->global_vmstate && qemu_ram_block_by_name("vga.vram")) {
+        error_setg(errp, "Only one global VGA device can be used at a time");
+        return false;
+    }
+
     memory_region_init_ram_nomigrate(&s->vram, obj, "vga.vram", s->vram_size,
-                           &error_fatal);
+                                     &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return false;
+    }
     vmstate_register_ram(&s->vram, s->global_vmstate ? NULL : DEVICE(obj));
     xen_register_framebuffer(&s->vram);
     s->vram_ptr = memory_region_get_ram_ptr(&s->vram);
@@ -2237,6 +2248,8 @@ void vga_common_init(VGACommonState *s, Object *obj)
     s->default_endian_fb = false;
 #endif
     vga_dirty_log_start(s);
+
+    return true;
 }
 
 static const MemoryRegionPortio vga_portio_list[] = {
diff --git a/hw/display/vga_int.h b/hw/display/vga_int.h
index 847e784ca6..305e700014 100644
--- a/hw/display/vga_int.h
+++ b/hw/display/vga_int.h
@@ -156,7 +156,7 @@ static inline int c6_to_8(int v)
     return (v << 2) | (b << 1) | b;
 }
 
-void vga_common_init(VGACommonState *s, Object *obj);
+bool vga_common_init(VGACommonState *s, Object *obj, Error **errp);
 void vga_init(VGACommonState *s, Object *obj, MemoryRegion *address_space,
               MemoryRegion *address_space_io, bool init_vga_ports);
 MemoryRegion *vga_init_io(VGACommonState *s, Object *obj,
diff --git a/hw/display/virtio-vga.c b/hw/display/virtio-vga.c
index 5a2f7a4540..7b55c8d0e7 100644
--- a/hw/display/virtio-vga.c
+++ b/hw/display/virtio-vga.c
@@ -108,7 +108,9 @@ static void virtio_vga_base_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
 
     /* init vga compat bits */
     vga->vram_size_mb = 8;
-    vga_common_init(vga, OBJECT(vpci_dev));
+    if (!vga_common_init(vga, OBJECT(vpci_dev), errp)) {
+        return;
+    }
     vga_init(vga, OBJECT(vpci_dev), pci_address_space(&vpci_dev->pci_dev),
              pci_address_space_io(&vpci_dev->pci_dev), true);
     pci_register_bar(&vpci_dev->pci_dev, 0,
diff --git a/hw/display/vmware_vga.c b/hw/display/vmware_vga.c
index 0cc43a1f15..98c83474ad 100644
--- a/hw/display/vmware_vga.c
+++ b/hw/display/vmware_vga.c
@@ -1254,7 +1254,7 @@ static void vmsvga_init(DeviceState *dev, struct vmsvga_state_s *s,
                            &error_fatal);
     s->fifo_ptr = memory_region_get_ram_ptr(&s->fifo_ram);
 
-    vga_common_init(&s->vga, OBJECT(dev));
+    vga_common_init(&s->vga, OBJECT(dev), &error_fatal);
     vga_init(&s->vga, OBJECT(dev), address_space, io, true);
     vmstate_register(NULL, 0, &vmstate_vga_common, &s->vga);
     s->new_depth = 32;
diff --git a/ui/gtk.c b/ui/gtk.c
index 1b24a67d79..c57c36749e 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -972,6 +972,10 @@ static gboolean gd_button_event(GtkWidget *widget, GdkEventButton *button,
         return TRUE;
     }
 
+    if (button->type == GDK_2BUTTON_PRESS || button->type == GDK_3BUTTON_PRESS) {
+        return TRUE;
+    }
+
     qemu_input_queue_btn(vc->gfx.dcl.con, btn,
                          button->type == GDK_BUTTON_PRESS);
     qemu_input_event_sync();
diff --git a/ui/vnc.c b/ui/vnc.c
index 3ccd33dedc..310a873c21 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3098,6 +3098,9 @@ static int vnc_refresh_server_surface(VncDisplay *vd)
     VncState *vs;
     int has_dirty = 0;
     pixman_image_t *tmpbuf = NULL;
+    unsigned long offset;
+    int x;
+    uint8_t *guest_ptr, *server_ptr;
 
     struct timeval tv = { 0, 0 };
 
@@ -3106,6 +3109,13 @@ static int vnc_refresh_server_surface(VncDisplay *vd)
         has_dirty = vnc_update_stats(vd, &tv);
     }
 
+    offset = find_next_bit((unsigned long *) &vd->guest.dirty,
+                           height * VNC_DIRTY_BPL(&vd->guest), 0);
+    if (offset == height * VNC_DIRTY_BPL(&vd->guest)) {
+        /* no dirty bits in guest surface */
+        return has_dirty;
+    }
+
     /*
      * Walk through the guest dirty map.
      * Check and copy modified bits from guest to server surface.
@@ -3130,15 +3140,6 @@ static int vnc_refresh_server_surface(VncDisplay *vd)
     line_bytes = MIN(server_stride, guest_ll);
 
     for (;;) {
-        int x;
-        uint8_t *guest_ptr, *server_ptr;
-        unsigned long offset = find_next_bit((unsigned long *) &vd->guest.dirty,
-                                             height * VNC_DIRTY_BPL(&vd->guest),
-                                             y * VNC_DIRTY_BPL(&vd->guest));
-        if (offset == height * VNC_DIRTY_BPL(&vd->guest)) {
-            /* no more dirty bits */
-            break;
-        }
         y = offset / VNC_DIRTY_BPL(&vd->guest);
         x = offset % VNC_DIRTY_BPL(&vd->guest);
 
@@ -3177,6 +3178,13 @@ static int vnc_refresh_server_surface(VncDisplay *vd)
         }
 
         y++;
+        offset = find_next_bit((unsigned long *) &vd->guest.dirty,
+                               height * VNC_DIRTY_BPL(&vd->guest),
+                               y * VNC_DIRTY_BPL(&vd->guest));
+        if (offset == height * VNC_DIRTY_BPL(&vd->guest)) {
+            /* no more dirty bits */
+            break;
+        }
     }
     qemu_pixman_image_unref(tmpbuf);
     return has_dirty;