322908 - ASSERTION: NS_Alloc of size 0: 'size'

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Martijn Wargers (dead)]

In an updated trunk build, I get this assertion when clicking on the submit button in the testcase:
###!!! ASSERTION: NS_Alloc of size 0: 'size', file c:/mozilla/mozilla/xpcom/base
/nsMemoryImpl.cpp, line 335

I don't get this with a debug build from a few weeks earlier.

Comment 1

[Boris Zbarsky [:bzbarsky]]

This is fallout from bug 318193 -- the form code is calling NS_NewByteInputStream and passing it an empty string (which seems perfectly reasonable).  nsStringInputStream::SetData then calls NS_Alloc with the length of the string, which is 0.  That seems wrong, but I'm not sure what the right thing to do would be; we can't use null for the data.

Comment 2

[Darin Fisher]

The MSDN documentation for malloc says the following:

  "If size is 0, malloc allocates a zero-length item in the heap and returns a valid pointer to that item."

So, why is NS_Alloc asserting that size should not be zero?  I think the assertion is bogus.

Comment 3

[Darin Fisher]

Attachment: v1 patch

Remove bogus assertions: malloc(0) and realloc(ptr, 0) are both valid.

Comment 4

[Darin Fisher]

Attachment: v1.1 patch

Whoops.. we shouldn't be calling FlushMemory if NS_Realloc was used to free memory!

Comment 5

[Darin Fisher]

fixed-on-trunk