[PATCH] Finish devices after their finish callback returns

[Uli Schlachter]

The problem is that the finish callback might still have to work with the
device, so it can't be made unusable yet. This is in contrast to what
cairo_surface_finish() does, but when finishing a surface it's quite unlikely
that its cairo_surface_t still has to be passed around to functions outside of
the backend.

This "fixes" some problems with the xcb-surface-source test where
_cairo_surface_snapshot()-style snapshot breaks when the underlying
cairo_device_t is finished. (In the following backtrace, cairo_device_acquire
fails because the device's ->finished member is TRUE)

 #0  cairo_device_acquire (device=0x690f70) at cairo-device.c:414
 #1  0x00007ffff7b884fb in _cairo_xcb_connection_acquire (surface=0x69c610, use_shm=<value optimized out>, image_out=0x7fffffffcc58) at cairo-xcb-private.h:246
 #2  _get_image (surface=0x69c610, use_shm=<value optimized out>, image_out=0x7fffffffcc58) at cairo-xcb-surface.c:425
 #3  0x00007ffff7b893cf in _cairo_xcb_surface_acquire_source_image (abstract_surface=0x69c610, image_out=0x7fffffffcce8, image_extra=0x7fffffffcce0)
     at cairo-xcb-surface.c:561
 #4  0x00007ffff7b601d4 in _cairo_surface_acquire_source_image (surface=0x690f70, image_out=0x7fffffffcce8, image_extra=0x0) at cairo-surface.c:1458
 #5  0x00007ffff7b65dcf in _cairo_surface_snapshot_copy_on_write (surface=<value optimized out>) at cairo-surface-snapshot.c:125
 #6  0x00007ffff7b609b1 in _cairo_surface_detach_snapshot (snapshot=0x690f70) at cairo-surface.c:330
 #7  0x00007ffff7b606dc in _cairo_surface_detach_snapshots (surface=0x69c610) at cairo-surface.c:315
 #8  cairo_surface_flush (surface=0x69c610) at cairo-surface.c:1126
 #9  0x00007ffff7b6074d in cairo_surface_finish (surface=0x690f70) at cairo-surface.c:718
 #10 0x00007ffff7b881ff in _cairo_xcb_screen_finish (screen=0x691920) at cairo-xcb-screen.c:61
 #11 0x00007ffff7b8629c in _device_finish (device=0x690f70) at cairo-xcb-connection.c:546
 #12 0x0000000000446f7c in cleanup (data=0x69c370) at xcb-surface-source.c:47
 #13 0x00007ffff7b1e56a in _cairo_user_data_array_fini (array=0x693628) at cairo-array.c:390
 #14 0x00007ffff7b60868 in cairo_surface_destroy (surface=0x693600) at cairo-surface.c:651
 #15 0x0000000000447599 in draw (cr=0x7ffff7ddc288, width=<value optimized out>, height=<value optimized out>) at surface-source.c:149
 #16 0x000000000040c1c3 in cairo_test_for_target (ctx=0x7fffffffe640, target=0x669668, dev_offset=<value optimized out>, similar=<value optimized out>)
     at cairo-test.c:984
 #17 0x000000000040d997 in _cairo_test_context_run_for_target (ctx=<value optimized out>, target=<value optimized out>, similar=<value optimized out>,
     dev_offset=<value optimized out>) at cairo-test.c:1617
 #18 0x000000000040ee09 in _cairo_test_runner_draw (argc=<value optimized out>, argv=<value optimized out>) at cairo-test-runner.c:269
 #19 main (argc=<value optimized out>, argv=<value optimized out>) at cairo-test-runner.c:924

Signed-off-by: Uli Schlachter <psychon at znc.in>
---
 src/cairo-device.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cairo-device.c b/src/cairo-device.c
index a32b971..bbedba7 100644
--- a/src/cairo-device.c
+++ b/src/cairo-device.c
@@ -296,10 +296,10 @@ cairo_device_finish (cairo_device_t *device)
 
     cairo_device_flush (device);
 
-    device->finished = TRUE;
-
     if (device->backend->finish != NULL)
 	device->backend->finish (device);
+
+    device->finished = TRUE;
 }
 slim_hidden_def (cairo_device_finish);
 
-- 
1.7.2.3


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