The bug

Holding down Ctrl while pressing F3 + C will force crash the JVM instead of only Minecraft. However, there are several issues with the current implementation:

• Minecraft does not differentiate between a normal and a JVM force crash:
  • The user is not warned for a JVM force crash
  • The log file contains no indication at all that a JVM force crash was performed
• The generated JVM crash file has no indication at all that it was a force crash; you would manually have to look at the stack trace and deobfuscate it:

  EXCEPTION_ACCESS_VIOLATION
  
  j  org.lwjgl.system.MemoryUtil.memSet(JIJ)V+215
  J 23330 C1 dsc.b()V (146 bytes) @ 0x0000000005c5b044 [0x0000000005c5a6a0+0x9a4]
  J 22960 C2 dse.q()V (840 bytes) @ 0x0000000005845440 [0x0000000005843dc0+0x1680]
  J 22781 C2 dse.e(Z)V (1014 bytes) @ 0x0000000004eee150 [0x0000000004eed8e0+0x870]
  J 22890% C1 dse.e()V (208 bytes) @ 0x000000000523f10c [0x000000000523ee00+0x30c]
  j  net.minecraft.client.main.Main.main([Ljava/lang/String;)V+1366
  

This can also make diagnosing user problems more difficult when they are told to cause a force crash but accidentially perform a JVM force crash.

Reproduction steps

1. Perform a JVM force crash by holding down Ctrl + F3 + C
   Note: Some keyboards might have technical limitations which prevent them from correctly detecting that you are holding down multiple keys at the same time.
2. Look at the logged chat message, the log messages and the JVM crash report
   None of these indicate that a force JVM crash (instead of a regular force crash) was performed