Debugging heap corruption

[Walter Bright]

Vladimir Panteleev wrote:
> I noticed that Phobos's GC has some debug code for "underrun/overrrun protection" [sic]
 > in phobos\internal\gc\gcx.d, however I found that the code is 
unfinished. For some
 > reason the corresponding code is put in "version (SENTINEL)" blocks, 
instead of
 > "debug (SENTINEL)" ones - which would explain why it never worked 
(there is also a typo
 > in code on line 567). Even with those obvious mistakes fixed, I have 
no idea how much
 > work would be required to get the SENTINEL debug option working, 
since it's interfering
 > with other language features such as array concatenation, and firing 
off false alarms.

Please post any bugs you've found or patches you've made to bugzilla.