Not reproducible here. Also, there's no way for an external to crash TCC unless they're injecting a (crashing) dll into the TCC process. (Unless Git has discovered a way to subvert the hardward restrictions on process boundaries!)
What is the exact exception info you're seeing?
Here you go. If you would like to provide debug symbols, I'd be happy to get a better call stack.
> takecmd.dll!1006bef8()
[Frames below may be incorrect and/or missing, no symbols loaded for takecmd.dll]
takecmd.dll!10002fbc()
1006BED0 mov dword ptr [edi+ecx*4-18h],eax
1006BED4 mov eax,dword ptr [esi+ecx*4-14h]
1006BED8 mov dword ptr [edi+ecx*4-14h],eax
1006BEDC mov eax,dword ptr [esi+ecx*4-10h]
1006BEE0 mov dword ptr [edi+ecx*4-10h],eax
1006BEE4 mov eax,dword ptr [esi+ecx*4-0Ch]
1006BEE8 mov dword ptr [edi+ecx*4-0Ch],eax
1006BEEC mov eax,dword ptr [esi+ecx*4-8]
1006BEF0 mov dword ptr [edi+ecx*4-8],eax
1006BEF4 mov eax,dword ptr [esi+ecx*4-4]
>>>>>>1006BEF8 mov dword ptr [edi+ecx*4-4],eax
1006BEFC lea eax,[ecx*4]
1006BF03 add esi,eax
1006BF05 add edi,eax
EAX = 00000000 EBX = 00000000 ECX = 00000001 EDX = 00000000 ESI = 04601BC0 EDI = 0040C3F0 EIP = 1006BEF8 ESP = 016B3A9C EBP = 016B3AA4 EFL = 00010297
0040C3F0 = 00000000
0 > 6340 Main Thread Main Thread 1006bef8 Normal 0
0 6752 Worker Thread _TppWaiterpThread@4 _NtWaitForMultipleObjects@20 Normal 0
0 6464 Worker Thread Win32 Thread _NtUserGetMessage@16 Normal 0
'tcc.exe': Loaded 'C:\Program Files (x86)\JPSoft\TCCLE12\tcc.exe', Binary was not built with debug information.
'tcc.exe': Loaded 'C:\Windows\SysWOW64\ntdll.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\kernel32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\KernelBase.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Program Files (x86)\JPSoft\TCCLE12\takecmd.dll', Binary was not built with debug information.
'tcc.exe': Loaded 'C:\Windows\SysWOW64\winmm.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\msvcrt.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\user32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\gdi32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\lpk.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\usp10.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\advapi32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\sechost.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\rpcrt4.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\sspicli.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\cryptbase.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\mpr.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\winsxs\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7600.16385_none_421189da2b7fabfc\comctl32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\shlwapi.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\psapi.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\netapi32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\netutils.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\srvcli.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\wkscli.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\browcli.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Program Files (x86)\JPSoft\TCCLE12\onig.dll', Binary was not built with debug information.
'tcc.exe': Loaded 'C:\Windows\SysWOW64\comdlg32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\shell32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\ole32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\oleaut32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\imm32.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\msctf.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\uxtheme.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Program Files (x86)\JPSoft\TCCLE12\English.dll', Binary was not built with debug information.
'tcc.exe': Loaded 'C:\Windows\SysWOW64\dwmapi.dll', Symbols loaded (source information stripped).
'tcc.exe': Loaded 'C:\Windows\SysWOW64\apphelp.dll', Symbols loaded (source information stripped).
First-chance exception at 0x1006bef8 in tcc.exe: 0xC0000005: Access violation writing location 0x0040c3f0.
Unhandled exception at 0x1006bef8 in tcc.exe: 0xC0000005: Access violation writing location 0x0040c3f0.