[vte/wip/sixels] terminal: Handle out-of-memory gracefully for image buffers

[Hans Petter Jansson <hansp src gnome org>]

commit 1ecc8ae614958470752088b57ea84c92c98df0af
Author: Hans Petter Jansson <hpj cl no>
Date:   Fri Jun 26 18:53:10 2020 +0200

    terminal: Handle out-of-memory gracefully for image buffers

 src/vteseq.cc | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)
---
diff --git a/src/vteseq.cc b/src/vteseq.cc
index f5dc37c0..c9be3991 100644
--- a/src/vteseq.cc
+++ b/src/vteseq.cc
@@ -4366,12 +4366,13 @@ Terminal::DECSIXEL(vte::parser::Sequence const& seq)
                sixel_parser_deinit(&m_sixel_state);
                return;
        }
-       pixels = (unsigned char *)g_malloc(m_sixel_state.image.width * m_sixel_state.image.height * 4);
+       pixels = (unsigned char *)g_try_malloc(m_sixel_state.image.width * m_sixel_state.image.height * 4);
        if (!pixels) {
                sixel_parser_deinit(&m_sixel_state);
                return;
        }
        if (sixel_parser_finalize(&m_sixel_state, pixels) < 0) {
+                g_free(pixels);
                sixel_parser_deinit(&m_sixel_state);
                return;
        }
@@ -4389,21 +4390,24 @@ Terminal::DECSIXEL(vte::parser::Sequence const& seq)
        /* Convert to device-compatible surface for m_widget */
 
        image_surface = cairo_image_surface_create_for_data (pixels, CAIRO_FORMAT_ARGB32, pixelwidth, 
pixelheight, pixelwidth * 4);
-
-        /* FIXME-hpj: Handle out-of-memory gracefully */
-       g_assert (image_surface);
+        if (!image_surface) {
+                g_free(pixels);
+                return;
+        }
 
        surface = gdk_window_create_similar_surface (gtk_widget_get_window (m_widget), 
CAIRO_CONTENT_COLOR_ALPHA, pixelwidth, pixelheight);
-
-        /* FIXME-hpj: Handle out-of-memory gracefully */
-       g_assert (surface);
+        if (!surface) {
+                cairo_surface_destroy(image_surface);
+                g_free(pixels);
+                return;
+        }
 
        cr = cairo_create (surface);
        cairo_set_source_surface (cr, image_surface, 0, 0);
        cairo_paint (cr);
        cairo_destroy (cr);
        cairo_surface_destroy (image_surface);
-       free (pixels);
+       g_free(pixels);
 
        /* Append image to Ring */