Error log simple dragged vehicle crashes into companion

DEBUG    : map::board_vehicle: passenger (Cecil Saldivar) is already there

 FUNCTION : void map::board_vehicle(const tripoint&, player*)
 FILE     : src/map.cpp
 LINE     : 959

-------
debug.log:

-----------------------------------------
13:46:49.515 : Starting log.
13:46:49.515 INFO : Cataclysm DDA version 0.E-2
13:46:49.515 WARNING : Error while setlocale(LC_ALL, '').
13:46:49.515 INFO : SDL version used during compile is 2.0.5
13:46:49.515 INFO : SDL version used during linking and in runtime is 2.0.5
13:46:49.618 INFO : Number of render drivers on your system: 4
13:46:49.618 INFO : Render driver: 0/direct3d
13:46:49.618 INFO : Render driver: 1/direct3d11
13:46:49.618 INFO : Render driver: 2/opengl
13:46:49.618 INFO : Render driver: 3/software
13:46:49.636 INFO : Active renderer: 0/direct3d
13:46:50.044 INFO : USE_COLOR_MODULATED_TEXTURES is set to 0
13:46:50.099 INFO : Language is set to: 'en'
13:46:50.525 WARNING : opendir [./mods/] failed with "No such file or directory".
13:46:54.390 WARNING : opendir [./save/Old Saybrook/mods] failed with "No such file or directory".
13:46:56.411 INFO : Loaded tileset: retrodays
17:33:52.716 ERROR : (error message will follow backtrace)
  #0
    (dbghelp: @0x620c16[cataclysm-tiles.exe+0x220c16]), 
    (libbacktrace: Z21debug_write_backtraceRSo+0x56@0x620c16),
    (libbacktrace: 0x620c16    [unknown src]:0    [unknown func]),
  #1
    (dbghelp: @0x6216aa[cataclysm-tiles.exe+0x2216aa]), 
    (libbacktrace: Z8DebugLog10DebugLevel10DebugClass+0x34a@0x6216aa),
    (libbacktrace: 0x6216aa    [unknown src]:0    [unknown func]),
  #2
    (dbghelp: @0x6245f6[cataclysm-tiles.exe+0x2245f6]), 
    (libbacktrace: Z12realDebugmsgPKcS0_S0_RKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x76@0x6245f6),
    (libbacktrace: 0x6245f6    [unknown src]:0    [unknown func]),
  #3
    (dbghelp: IMG_LoadWEBP_RW+0x11ab5a@0x125edda[cataclysm-tiles.exe+0xe5edda]), 
    (libbacktrace: Z12realDebugmsgIJNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEvPKcS7_S7_S7_DpOT_+0x3a@0x125edda),
    (libbacktrace: 0x125edda    [unknown src]:0    [unknown func]),
  #4
    (dbghelp: @0x9b0b30[cataclysm-tiles.exe+0x5b0b30]), 
    (libbacktrace: ZN3map13board_vehicleERK8tripointP6player+0xf0@0x9b0b30),
    (libbacktrace: 0x9b0b30    [unknown src]:0    [unknown func]),
  #5
    (dbghelp: @0x71e768[cataclysm-tiles.exe+0x31e768]), 
    (libbacktrace: ZN4game12place_playerERK8tripoint+0xde8@0x71e768),
    (libbacktrace: 0x71e768    [unknown src]:0    [unknown func]),
  #6
    (dbghelp: @0x726909[cataclysm-tiles.exe+0x326909]), 
    (libbacktrace: ZN4game9walk_moveERK8tripoint+0xff9@0x726909),
    (libbacktrace: 0x726909    [unknown src]:0    [unknown func]),
  #7
    (dbghelp: @0x4bd5a4[cataclysm-tiles.exe+0xbd5a4]), 
    (libbacktrace: ZN13avatar_action4moveER6avatarR3mapiii+0x14a4@0x4bd5a4),
    (libbacktrace: 0x4bd5a4    [unknown src]:0    [unknown func]),
  #8
    (dbghelp: @0x771f9c[cataclysm-tiles.exe+0x371f9c]), 
    (libbacktrace: ZN4game13handle_actionEv+0x4cfc@0x771f9c),
    (libbacktrace: 0x771f9c    [unknown src]:0    [unknown func]),
  #9
    (dbghelp: @0x74115f[cataclysm-tiles.exe+0x34115f]), 
    (libbacktrace: ZN4game7do_turnEv+0xb9f@0x74115f),
    (libbacktrace: 0x74115f    [unknown src]:0    [unknown func]),
  #10
    (dbghelp: IMG_LoadWEBP_RW+0x67a6b8@0x17be938[cataclysm-tiles.exe+0x13be938]), 
    (libbacktrace: main+0x10e8@0x17be938),
    (libbacktrace: 0x17be938    [unknown src]:0    [unknown func]),
  #11
    (dbghelp: @0x4013ed[cataclysm-tiles.exe+0x13ed]), 
    (libbacktrace: _tmainCRTStartup+0x23d@0x4013ed),
    (libbacktrace: 0x4013ed    /home/narc/src/mxe/tmp-gcc-x86_64-w64-mingw32.static/gcc-5.4.0.build_/mingw-w64-v5.0.2/mingw-w64-crt/crt/crtexe.c:336    __tmainCRTStartup),
  #12
    (dbghelp: @0x4014fb[cataclysm-tiles.exe+0x14fb]), 
    (libbacktrace: WinMainCRTStartup+0x1b@0x4014fb),
    (libbacktrace: 0x4014fb    /home/narc/src/mxe/tmp-gcc-x86_64-w64-mingw32.static/gcc-5.4.0.build_/mingw-w64-v5.0.2/mingw-w64-crt/crt/crtexe.c:186    WinMainCRTStartup),
  #13
    (dbghelp: BaseThreadInitThunk+0x14@0x7ffc58557bd4[KERNEL32.DLL+0x17bd4]), 
    (backtrace_syminfo failed: errno = -1, msg = no symbol table in PE/COFF executable),
    (backtrace_pcinfo failed: errno = -1, msg = no debug info in PE/COFF executable),
  #14
    (dbghelp: RtlUserThreadStart+0x21@0x7ffc59e0ce51[ntdll.dll+0x6ce51]), 
    (backtrace_syminfo failed: errno = -1, msg = no symbol table in PE/COFF executable),
    (backtrace_pcinfo failed: errno = -1, msg = no debug info in PE/COFF executable),
Backtrace emission took 0 seconds.
src/map.cpp:959 [void map::board_vehicle(const tripoint&, player*)] map::board_vehicle: passenger (Cecil Saldivar) is already there

Situation: The PC is dragging a simple vehicle consisting of a light frame with a travios and harness & tackle, but keeps bumping into the companion (Cecil Saldivar) when I try to turn. I grabbed the “box” part, rather than the harness part.

Edit: An important part is probably that my simple two tile vehicle was two tiles wide instead of two tiles long as intended, so it kept swinging “sideways”, bumping into the companion.