epiphany segfaults in certificate error page with webkit2gtk 2.19.5

How to reproduce:

1. Visit some site with invalid certificate
   eg: https://dev.openwrt.org/

2. In the error page shown, click "Technical Information" -> "Accept Risk and Proceed"

Result:

epiphany segfaults with the following printed to terminal:

1   0x7ff0f1b1c437 /home/sadiq/jhbuild/install/lib/libjavascriptcoregtk-4.0.so.18(+0xb26437) [0x7ff0f1b1c437]
2   0x7ff0f1a13be5 /home/sadiq/jhbuild/install/lib/libjavascriptcoregtk-4.0.so.18(+0xa1dbe5) [0x7ff0f1a13be5]
3   0x7ff0f18f317b /home/sadiq/jhbuild/install/lib/libjavascriptcoregtk-4.0.so.18(+0x8fd17b) [0x7ff0f18f317b]
4   0x7ff0f10aaafc /home/sadiq/jhbuild/install/lib/libjavascriptcoregtk-4.0.so.18(JSValueToNumber+0x3c) [0x7ff0f10aaafc]
5   0x7ff0f891628b /home/sadiq/jhbuild/install/lib/epiphany/libephymain.so(ephy_embed_utils_get_js_result_as_number+0x3f) [0x7ff0f891628b]
6   0x7ff0f8912f9d /home/sadiq/jhbuild/install/lib/epiphany/libephymain.so(+0x74f9d) [0x7ff0f8912f9d]
7   0x7ff0f84145b2 /home/sadiq/jhbuild/install/lib/libgobject-2.0.so.0(g_cclosure_marshal_VOID__BOXED+0xd5) [0x7ff0f84145b2]
8   0x7ff0f840fa18 /home/sadiq/jhbuild/install/lib/libgobject-2.0.so.0(g_closure_invoke+0x18a) [0x7ff0f840fa18]
9   0x7ff0f842d47a /home/sadiq/jhbuild/install/lib/libgobject-2.0.so.0(+0x2e47a) [0x7ff0f842d47a]
10  0x7ff0f842c787 /home/sadiq/jhbuild/install/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x11fd) [0x7ff0f842c787]
11  0x7ff0f842cd0a /home/sadiq/jhbuild/install/lib/libgobject-2.0.so.0(g_signal_emit+0xa6) [0x7ff0f842cd0a]
12  0x7ff0f273bbc9 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x946bc9) [0x7ff0f273bbc9]
13  0x7ff0f25c6cf3 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x7d1cf3) [0x7ff0f25c6cf3]
14  0x7ff0f28bfca6 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0xacaca6) [0x7ff0f28bfca6]
15  0x7ff0f245e72e /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x66972e) [0x7ff0f245e72e]
16  0x7ff0f25570ef /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x7620ef) [0x7ff0f25570ef]
17  0x7ff0f2458ac0 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x663ac0) [0x7ff0f2458ac0]
18  0x7ff0f2458e1c /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x663e1c) [0x7ff0f2458e1c]
19  0x7ff0f49049d7 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x2b0f9d7) [0x7ff0f49049d7]
20  0x7ff0f4948f99 /home/sadiq/jhbuild/install/lib/libwebkit2gtk-4.0.so.37(+0x2b53f99) [0x7ff0f4948f99]
21  0x7ff0f8125c72 /home/sadiq/jhbuild/install/lib/libglib-2.0.so.0(+0x55c72) [0x7ff0f8125c72]
22  0x7ff0f8126af7 /home/sadiq/jhbuild/install/lib/libglib-2.0.so.0(g_main_context_dispatch+0x33) [0x7ff0f8126af7]
23  0x7ff0f8126cdb /home/sadiq/jhbuild/install/lib/libglib-2.0.so.0(+0x56cdb) [0x7ff0f8126cdb]
24  0x7ff0f8126d9f /home/sadiq/jhbuild/install/lib/libglib-2.0.so.0(g_main_context_iteration+0x4a) [0x7ff0f8126d9f]
25  0x7ff0f7dad6bb /home/sadiq/jhbuild/install/lib/libgio-2.0.so.0(g_application_run+0x327) [0x7ff0f7dad6bb]
26  0x564c434a3aa8 epiphany(+0x4aa8) [0x564c434a3aa8]
27  0x7ff0f68f7f2a /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xea) [0x7ff0f68f7f2a]
28  0x564c434a289a epiphany(+0x389a) [0x564c434a289a]


The culprit seems to be  line 4 JSValueToNumber. A segfault was happening in bijiben (in JSValueIsObject when a new note is created), a method of the same class. So I just tried, and the result is same.

As this happen on both cases, the issue may probably be in upstream.

Thanks