fileno implicitly converted to pointer

[LaMont Jones]

Binary package hint: fsl

Function `fileno' implicitly converted to pointer at wpng.c:279

Our automated build log filter[1] detected the problem(s) above that will
likely cause your package to segfault on 64-bit architectures (where the
size of a pointer is greater than the size of an integer.)

This is often due to a missing function prototype definition.
For more information, see [2].

Since use of implicitly converted pointers is always (eventually
and/or itermittantly) fatal to the application, they are errors.
Please correct them for your next upload.

[1] http://people.debian.org/~dannf/check-implicit-pointer-functions
[2] http://wiki.debian.org/ImplicitPointerConversions

[Graziano (graziano-giuliani-gmail)]

I was not able to reproduce any warning in compiling wpng.c using gcc 4.4.1-3ubuntu3 on karmic x86_64.

The fail line reported is:

[...]
279 if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
[...]

and personally I do not find errors in it.
The source file correctly includes stdio.h for prototypes:

typedef struct _IO_FILE FILE;
extern struct _IO_FILE *stdin;
FILE *fdopen(int fd, const char *mode);
int fileno(FILE *stream);

So we have an int coming from a call to fileno with the correct FILE structure pointer argument as input to the fdopen function which expects an integer. And gcc with -wall -pedantic does not report any error. Need to know which compiler version is used in the automatic test above.

[Michael Terry (mterry)]

The problem is that fsl is built with the -ansi flag. Thus, fdopen and fileno are not defined by default. In order to have them defined, either _GNU_SOURCE or _POSIX_SOURCE should be defined (exact list of symbols that would enable them are in their man pages).

Since many other files in the fsl source already define the pair of _GNU_SOURCE and POSIX_SOURCE for specific files, I just added them to the relevant wpng.c file (no patch system in the debian package, so I patched directly).

Will open a Debian bug too.

[Launchpad Janitor (janitor)]

This bug was fixed in the package fsl - 4.1.4-2ubuntu1

---------------
fsl (4.1.4-2ubuntu1) karmic; urgency=low

  * src/miscvis/wpng.c: Define _GNU_SOURCE to fix an ANSI C warning from
    the use of fdopen and fileno. LP: #402174

 -- Michael Terry <email address hidden> Thu, 10 Sep 2009 11:48:53 -0400