Symbol Editor: Open PDF, segfault (lp:#1829825)

[Original report](https://bugs.launchpad.net/bugs/1829825) created by **Jorge Neiva (jo-joven)**
```
How to reproduce:

kicad nightly -> Symbol Editor -> select MIC2026 -> click "show associated
datasheet or document"

When you click, happen a segmentation fault.

dmesg:
[ 2400.270854] kicad[5809]: segfault at 168 ip 00007fcfd98ee4e6 sp
00007ffdf5e0a290 error 4 in _eeschema.kiface[7fcfd9203000+8fc000]

If the pdf link is https:// it works, and if it is http:// happens
segmentation fault.


$ coredumpctl dump
           PID: 7003 (kicad)
           UID: 1000 (jneiva)
           GID: 1000 (jneiva)
        Signal: 11 (SEGV)
     Timestamp: Tue 2019-05-21 09:01:47 WEST (1min 25s ago)
  Command Line: /usr/lib/kicad-nightly/bin/kicad
    Executable: /usr/lib/kicad-nightly/bin/kicad
 Control Group: /user.slice/user-1000.slice/session-c2.scope
          Unit: session-c2.scope
         Slice: user-1000.slice
       Session: c2
     Owner UID: 1000 (jneiva)
       Boot ID: a51103be09f74c8ca8118d65ca05094e
    Machine ID: 48988a50738e4c2a8caac722dd87aac6
      Hostname: jneiva
       Storage:
/var/lib/systemd/coredump/core.kicad.1000.a51103be09f74c8ca8118d65ca05094e.7003.1558425707000000.lz4
       Message: Process 7003 (kicad) of user 1000 dumped core.

                Stack trace of thread 7003:
                #0  0x00007fbb150ba4e6 n/a (_eeschema.kiface)
                #1  0x00007fbb150a1e31 n/a (_eeschema.kiface)
                #2  0x00007fbb14f6d8d5 n/a (_eeschema.kiface)
                #3  0x00007fbb372834be
_ZN12wxEvtHandler23ProcessEventIfMatchesIdERK21wxEventTableEntryBasePS_R7wxEvent
(libwx_baseu-3.0.so.0)
                #4  0x00007fbb372835c3
_ZN16wxEventHashTable11HandleEventER7wxEventP12wxEvtHandler
(libwx_baseu-3.0.so.0)
                #5  0x00007fbb3728398b
_ZN12wxEvtHandler11TryHereOnlyER7wxEvent (libwx_baseu-3.0.so.0)
                #6  0x00007fbb15025afb n/a (_eeschema.kiface)
                #7  0x00007fbb37283783
_ZN12wxEvtHandler10DoTryChainER7wxEvent (libwx_baseu-3.0.so.0)
                #8  0x00007fbb37283a75
_ZN12wxEvtHandler12ProcessEventER7wxEvent (libwx_baseu-3.0.so.0)
                #9  0x00007fbb372837d7
_ZN12wxEvtHandler18SafelyProcessEventER7wxEvent (libwx_baseu-3.0.so.0)
                #10 0x00007fbb37a4718d n/a (libwx_gtk3u_core-3.0.so.0)
                #11 0x00007fbb3509010d g_closure_invoke
(libgobject-2.0.so.0)
                #12 0x00007fbb350a305e n/a (libgobject-2.0.so.0)
                #13 0x00007fbb350ab715 g_signal_emit_valist
(libgobject-2.0.so.0)
                #14 0x00007fbb350ac12f g_signal_emit (libgobject-2.0.so.0)
                #15 0x00007fbb35952172 gtk_widget_map (libgtk-3.so.0)
                #16 0x00007fbb3596814f n/a (libgtk-3.so.0)
                #17 0x00007fbb35090346 n/a (libgobject-2.0.so.0)
                #18 0x00007fbb350ab9ff g_signal_emit_valist
(libgobject-2.0.so.0)
                #19 0x00007fbb350ac12f g_signal_emit (libgobject-2.0.so.0)
                #20 0x00007fbb35952172 gtk_widget_map (libgtk-3.so.0)
                #21 0x00007fbb3595fdbd n/a (libgtk-3.so.0)
                #22 0x00007fbb3509010d g_closure_invoke
(libgobject-2.0.so.0)
                #23 0x00007fbb350a312e n/a (libgobject-2.0.so.0)
                #24 0x00007fbb350ab715 g_signal_emit_valist
(libgobject-2.0.so.0)
                #25 0x00007fbb350ac12f g_signal_emit (libgobject-2.0.so.0)
                #26 0x00007fbb3594c0c6 gtk_widget_show (libgtk-3.so.0)
                #27 0x00007fbb3580c60d n/a (libgtk-3.so.0)
                #28 0x00007fbb3580caff gtk_menu_popup (libgtk-3.so.0)
                #29 0x00007fbb379eac61 _ZN8wxWindow11DoPopupMenuEP6wxMenuii
(libwx_gtk3u_core-3.0.so.0)
                #30 0x00007fbb37baa3f3
_ZN12wxWindowBase9PopupMenuEP6wxMenuii (libwx_gtk3u_core-3.0.so.0)
                #31 0x00007fbb14cc47c3 n/a (_eeschema.kiface)
                #32 0x00007fbb372834be
_ZN12wxEvtHandler23ProcessEventIfMatchesIdERK21wxEventTableEntryBasePS_R7wxEvent
(libwx_baseu-3.0.so.0)
                #33 0x00007fbb372835c3
_ZN16wxEventHashTable11HandleEventER7wxEventP12wxEvtHandler
(libwx_baseu-3.0.so.0)
                #34 0x00007fbb3728398b
_ZN12wxEvtHandler11TryHereOnlyER7wxEvent (libwx_baseu-3.0.so.0)
                #35 0x00007fbb15025afb n/a (_eeschema.kiface)
                #36 0x00007fbb37283783
_ZN12wxEvtHandler10DoTryChainER7wxEvent (libwx_baseu-3.0.so.0)
                #37 0x00007fbb37283a75
_ZN12wxEvtHandler12ProcessEventER7wxEvent (libwx_baseu-3.0.so.0)
                #38 0x00007fbb37ba683b _ZN12wxWindowBase8TryAfterER7wxEvent
(libwx_gtk3u_core-3.0.so.0)
                #39 0x00007fbb3869a9e8
_ZN12wxAuiToolBar8OnLeftUpER12wxMouseEvent (libwx_gtk3u_aui-3.0.so.0)
                #40 0x00007fbb372834be
_ZN12wxEvtHandler23ProcessEventIfMatchesIdERK21wxEventTableEntryBasePS_R7wxEvent
(libwx_baseu-3.0.so.0)
                #41 0x00007fbb372835c3
_ZN16wxEventHashTable11HandleEventER7wxEventP12wxEvtHandler
(libwx_baseu-3.0.so.0)
                #42 0x00007fbb3728398b
_ZN12wxEvtHandler11TryHereOnlyER7wxEvent (libwx_baseu-3.0.so.0)
                #43 0x00007fbb37283a13
_ZN12wxEvtHandler19ProcessEventLocallyER7wxEvent (libwx_baseu-3.0.so.0)
                #44 0x00007fbb37283a75
_ZN12wxEvtHandler12ProcessEventER7wxEvent (libwx_baseu-3.0.so.0)
                #45 0x00007fbb372837d7
_ZN12wxEvtHandler18SafelyProcessEventER7wxEvent (libwx_baseu-3.0.so.0)
                #46 0x00007fbb379efd4b n/a (libwx_gtk3u_core-3.0.so.0)
                #47 0x00007fbb357fb7fb n/a (libgtk-3.so.0)
                #48 0x00007fbb3509010d g_closure_invoke
(libgobject-2.0.so.0)
                #49 0x00007fbb350a305e n/a (libgobject-2.0.so.0)
                #50 0x00007fbb350ab0af g_signal_emit_valist
(libgobject-2.0.so.0)
                #51 0x00007fbb350ac12f g_signal_emit (libgobject-2.0.so.0)
                #52 0x00007fbb35943534 n/a (libgtk-3.so.0)
                #53 0x00007fbb357f886e n/a (libgtk-3.so.0)
                #54 0x00007fbb357fa948 gtk_main_do_event (libgtk-3.so.0)
                #55 0x00007fbb3530b765 n/a (libgdk-3.so.0)
                #56 0x00007fbb3533bf92 n/a (libgdk-3.so.0)
                #57 0x00007fbb34627417 g_main_context_dispatch
(libglib-2.0.so.0)
                #58 0x00007fbb34627650 n/a (libglib-2.0.so.0)
                #59 0x00007fbb34627962 g_main_loop_run (libglib-2.0.so.0)
                #60 0x00007fbb357f9a25 gtk_main (libgtk-3.so.0)
                #61 0x00007fbb379ce895 _ZN14wxGUIEventLoop5DoRunEv
(libwx_gtk3u_core-3.0.so.0)
                #62 0x00007fbb3713fa93 _ZN15wxEventLoopBase3RunEv
(libwx_baseu-3.0.so.0)
                #63 0x00007fbb371070a6 _ZN16wxAppConsoleBase8MainLoopEv
(libwx_baseu-3.0.so.0)

                Stack trace of thread 7020:
                #0  0x00007fbb35fe6bf9 __GI___poll (libc.so.6)
                #1  0x00007fbb346275c9 n/a (libglib-2.0.so.0)
                #2  0x00007fbb346276dc g_main_context_iteration
(libglib-2.0.so.0)
                #3  0x00007fbb34627721 n/a (libglib-2.0.so.0)
                #4  0x00007fbb3464f195 n/a (libglib-2.0.so.0)
                #5  0x00007fbb362ca6db start_thread (libpthread.so.0)
                #6  0x00007fbb35ff388f __clone (libc.so.6)

                Stack trace of thread 7021:
                #0  0x00007fbb35fe6bf9 __GI___poll (libc.so.6)
                #1  0x00007fbb346275c9 n/a (libglib-2.0.so.0)
                #2  0x00007fbb34627962 g_main_loop_run (libglib-2.0.so.0)
                #3  0x00007fbb302af0e6 n/a (libgio-2.0.so.0)
                #4  0x00007fbb3464f195 n/a (libglib-2.0.so.0)
                #5  0x00007fbb362ca6db start_thread (libpthread.so.0)
                #6  0x00007fbb35ff388f __clone (libc.so.6)

                Stack trace of thread 7027:
                #0  0x00007fbb35fed839 syscall (libc.so.6)
                #1  0x00007fbb3466d89a g_cond_wait_until (libglib-2.0.so.0)
                #2  0x00007fbb345fa571 n/a (libglib-2.0.so.0)
                #3  0x00007fbb345fab2c g_async_queue_timeout_pop
(libglib-2.0.so.0)
                #4  0x00007fbb3464fc3e n/a (libglib-2.0.so.0)
                #5  0x00007fbb3464f195 n/a (libglib-2.0.so.0)
                #6  0x00007fbb362ca6db start_thread (libpthread.so.0)
                #7  0x00007fbb35ff388f __clone (libc.so.6)
Refusing to dump core to tty (use shell redirection or specify --output).


kicad version:

Application: KiCad
Version: 6.0.0-unknown-f21face~100~ubuntu18.04.1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.58.0 OpenSSL/1.1.0g zlib/1.2.11 libidn2/2.0.4 libpsl/0.19.1
(+libidn2/2.0.4) nghttp2/1.30.0 librtmp/2.3
Platform: Linux 4.15.0-50-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.22
    Boost: 1.65.1
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.58.0
    Compiler: GCC 7.4.0 with C++ ABI 1011

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=ON
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON
```
Original tags: eeschema

Story points: 6.0