The differ() function used strerror_r() instead of strerror() because
it allowed the error message to be directly copied in to a buffer.
This causes two issues under Linux.
* There are two versions of strerror_r() available an XSI-compliant
version which returns an 'int' error code. And a GNU-specific
version which return a 'char *' to the resulting error string.
int strerror_r(int errnum, char *buf, size_t buflen); /* XSI */
char *strerror_r(int errnum, char *buf, size_t buflen); /* GNU */
* The most recent versions of strerror_r() are annotated with the
warn_unused_result attribute. This causes the following warning
since the upstream implementation casts the result to void.
warning: ignoring return value of 'strerror_r', declared with
attribute warn_unused_result [-Wunused-result]
The cleanest way to resolve both of these problems is just to use
strerror() and make a copy of the result in to the buffer. This
resolves both issues and this is the only instance of strerror_r()
in the code base.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1231