Small fixes

[bibendovsky]

• Fixed dereferencing null pointer in oggpack_writeinit
• Fixed type cast in ogg_page_serialno and ogg_page_pageno

[petterreinholdtsen]

This do not look correct. If malloc() fail, I doubt b->storage should get a non-zero value as the there is no storage available.

[bibendovsky]

This do not look correct. If malloc() fail, I doubt b->storage should get a non-zero value as the there is no storage available.

The fix do the check for a null. You can see this under the review conversation.

[petterreinholdtsen]

I do not understand your comment. I see the addition of if(b->buffer) in your patch, but fail to see how this properly handle the case where malloc() return NULL, as it seem incomplete and returning a misleading state from the oggpack_writeinit() method. Why is your edition still modifying b->storage if there is no memory area pointed to by b->buffer?

[petterreinholdtsen]

I created https://gitlab.xiph.org/xiph/ogg/-/merge_requests/26 with my proposed fix for the same issue, including updating the documentation to mention that the method can fail.

[bibendovsky]

I do not understand your comment. I see the addition of if(b->buffer) in your patch, but fail to see how this properly handle the case where malloc() return NULL

Conditional operator if (b->buffer) prevents from writing '\0' into b->buffer when it is null.

but fail to see how this properly handle the case where malloc() return NULL, as it seem incomplete and returning a misleading state from the oggpack_writeinit() method.

The commit do exactly what it says - nothing more, nothing less.
I could add another commit to address this exact issue (the incomplete state).

Why is your edition still modifying b->storage if there is no memory area pointed to by b->buffer?

That was in original code.

[petterreinholdtsen]

[Boris I. Bendovsky]

The commit do exactly what it says - nothing more, nothing less.

No worries. I believe that part of this pull request is wrong, and suggest to drop the commit from this set of changes. As mentioned earlier, I passed what I believe is a more correct change upstream to gitlab.xiph.org.

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-- Happy hacking Petter Reinholdtsen