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Bug 3764 - SDL_iconv_string doesn't properly signal an error with invalid input sizes
Summary: SDL_iconv_string doesn't properly signal an error with invalid input sizes
Status: ASSIGNED
Alias: None
Product: SDL
Classification: Unclassified
Component: *don't know* (show other bugs)
Version: HG 2.0
Hardware: All All
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-08-21 15:36 UTC by Simon Hug
Modified: 2017-08-30 07:06 UTC (History)
0 users

See Also:

Attachments
A little test case for wrong usage of SDL_iconv_string. (1.81 KB, text/x-csrc)
2017-08-21 15:36 UTC, Simon Hug 		Details
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Description Simon Hug 2017-08-21 15:36:36 UTC 
Created attachment 2869 [details]
A little test case for wrong usage of SDL_iconv_string.

SDL_iconv_string can return without encoding all characters and then doesn't signal that an error happened, like returning NULL. This only seems to be possible if the user makes a mistake and calculates the size of the string wrong. The SDL implementation of iconv may throw SDL_ICONV_EINVAL in that case and SDL_iconv_string essentially just exits with the unfinished string.

SDL is not responsible for user error, but I think it should signal that something went wrong. If the last character is expected to be a terminating zero and it is missing, well... we all known to what kind of bugs that leads.

Since SDL_iconv_string allocates plenty of memory, I also propose that it always adds a terminating zero at the end.

The attached program converts a string four times and dumps the memory.

I did not test any iconv implementations outside of SDL yet. I'm guessing it's also a problem there.
Comment 1 Sam Lantinga 2017-08-30 07:06:43 UTC 
I agree this should be fixed, but I'd like to research what different platforms do in this case, and it doesn't need to hold up 2.0.6.