corresponding valgrind log

==30405== Invalid read of size 4
==30405==    at 0x507AF64: FT_Done_Face (ftobjs.c:2017)
==30405==    by 0x494EB0C: _ZL13_ft_done_facePv (CairoFontEngine.cc:37)
==30405==    by 0x4A661AF: _cairo_user_data_array_fini (cairo-array.c:378)
==30405==    by 0x4A6A0B2: cairo_font_face_destroy (cairo-font-face.c:144)
==30405==    by 0x4AB08AF: _cairo_ft_unscaled_font_destroy (cairo-ft-font.c:495)
==30405==    by 0x4A69E97: _cairo_unscaled_font_destroy (cairo-font-face.c:531)
==30405==    by 0x4A777E6: _cairo_scaled_font_fini (cairo-scaled-font.c:587)
==30405==    by 0x4A778AB: cairo_scaled_font_destroy (cairo-scaled-font.c:843)
==30405==    by 0x4A6B4E7: _cairo_gstate_unset_scaled_font (cairo-gstate.c:1219)
==30405==    by 0x4A6B53D: _cairo_gstate_set_font_face (cairo-gstate.c:1492)
==30405==    by 0x4A634CE: cairo_set_font_face (cairo.c:2688)
==30405==    by 0x4951F2D: CairoOutputDev::updateFont(GfxState*) (CairoOutputDev.cc:383)
==30405==  Address 0x70758d8 is 16 bytes inside a block of size 84 free'd
==30405==    at 0x4023B4A: free (vg_replace_malloc.c:323)
==30405==    by 0x4B455B5: g_free (gmem.c:190)
==30405==    by 0x4A3CFB9: pango_parse_markup (in /usr/lib/libpango-1.0.so.0.2101.2)
==30405==    by 0x458C796: (within /usr/lib/libgtk-x11-2.0.so.0.1303.0)
==30405==    by 0x4AD34CE: g_object_set_property (gobject.c:697)
==30405==    by 0x460A784: (within /usr/lib/libgtk-x11-2.0.so.0.1303.0)
==30405==    by 0x4610904: (within /usr/lib/libgtk-x11-2.0.so.0.1303.0)
==30405==    by 0x4610F04: (within /usr/lib/libgtk-x11-2.0.so.0.1303.0)
==30405==    by 0x49735DA: (within /usr/lib/libgdk-x11-2.0.so.0.1303.0)
==30405==    by 0x4B3B540: g_idle_dispatch (gmain.c:4168)
==30405==    by 0x4B3D437: g_main_context_dispatch (gmain.c:2063)
==30405==    by 0x4B4099A: g_main_context_iterate (gmain.c:2696)
==30405== 
==30405== Invalid read of size 4
==30405==    at 0x507A68F: FT_List_Find (ftutil.c:250)
==30405==    by 0x507AF88: FT_Done_Face (ftobjs.c:2023)
==30405==    by 0x494EB0C: _ZL13_ft_done_facePv (CairoFontEngine.cc:37)
==30405==    by 0x4A661AF: _cairo_user_data_array_fini (cairo-array.c:378)
==30405==    by 0x4A6A0B2: cairo_font_face_destroy (cairo-font-face.c:144)
==30405==    by 0x4AB08AF: _cairo_ft_unscaled_font_destroy (cairo-ft-font.c:495)
==30405==    by 0x4A69E97: _cairo_unscaled_font_destroy (cairo-font-face.c:531)
==30405==    by 0x4A777E6: _cairo_scaled_font_fini (cairo-scaled-font.c:587)
==30405==    by 0x4A778AB: cairo_scaled_font_destroy (cairo-scaled-font.c:843)
==30405==    by 0x4A6B4E7: _cairo_gstate_unset_scaled_font (cairo-gstate.c:1219)
==30405==    by 0x4A6B53D: _cairo_gstate_set_font_face (cairo-gstate.c:1492)
==30405==    by 0x4A634CE: cairo_set_font_face (cairo.c:2688)
==30405==  Address 0x5d8928f4 is not stack'd, malloc'd or (recently) free'd
==30405== 
==30405== Process terminating with default action of signal 11 (SIGSEGV)
==30405==  Access not within mapped region at address 0x5D8928F4
==30405==    at 0x507A68F: FT_List_Find (ftutil.c:250)
==30405==    by 0x507AF88: FT_Done_Face (ftobjs.c:2023)
==30405==    by 0x494EB0C: _ZL13_ft_done_facePv (CairoFontEngine.cc:37)
==30405==    by 0x4A661AF: _cairo_user_data_array_fini (cairo-array.c:378)
==30405==    by 0x4A6A0B2: cairo_font_face_destroy (cairo-font-face.c:144)
==30405==    by 0x4AB08AF: _cairo_ft_unscaled_font_destroy (cairo-ft-font.c:495)
==30405==    by 0x4A69E97: _cairo_unscaled_font_destroy (cairo-font-face.c:531)
==30405==    by 0x4A777E6: _cairo_scaled_font_fini (cairo-scaled-font.c:587)
==30405==    by 0x4A778AB: cairo_scaled_font_destroy (cairo-scaled-font.c:843)
==30405==    by 0x4A6B4E7: _cairo_gstate_unset_scaled_font (cairo-gstate.c:1219)
==30405==    by 0x4A6B53D: _cairo_gstate_set_font_face (cairo-gstate.c:1492)
==30405==    by 0x4A634CE: cairo_set_font_face (cairo.c:2688)