The bug

A certain Woodland Mansion always crash with StackOverflowError and get "cut" when running on a JVM with only 512 MB of RAM or less available.

How to reproduce

1. Launch Minecraft with the JVM argument: -Xmx512M, this limits the amount of memory available to the Java Virtual Machine (and thus the game) to a maximum of 512MB
2. Create a new world in Minecraft 1.12. Enter the seed -8913466909937400889 into the world generator seed blank. (Due to the 1.13 world generator overhaul, this seed is just for version 1.12 and below and is not going to generate the same terrain on 1.13 or later versions)
3. Use /locate Mansion command (make sure cheat is on) to find the nearest woodland Mansion at the spawn point.
4. Use /tp command to teleport the player to the coordinate given by the output of the command with y coordinate being 128.
5. After landing on the woodland mansion go around, explore, and you will eventually see the crash.
   Symptoms:
   After the crash, relaunch Minecraft and you will find the woodland Mansion being "cut" like my screenshots. (Some fatal chunks are replaced by normal roofed forest)

I tried this twice and get another crash report with the same error/exception and layout

Note: The mansion generates correctly with 1 GB (or more) maximum heap size (JVM arg: -Xmx1G)

Crash report

Description: Exception while updating neighbours

java.lang.StackOverflowError: Exception while updating neighbours
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(Unknown Source)
	at java.security.SecureClassLoader.defineClass(Unknown Source)
	at java.net.URLClassLoader.defineClass(Unknown Source)
	at java.net.URLClassLoader.access$100(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at ams.a(SourceFile:475)
	at ams.b(SourceFile:435)
	...