| Summary: | lgamma() pole error sets errno to EDOM, should be ERANGE | ||
|---|---|---|---|
| Product: | glibc | Reporter: | Michael Kerrisk <mtk.manpages> |
| Component: | math | Assignee: | Andreas Jaeger <aj> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | glibc-bugs |
| Priority: | P2 | Flags: | fweimer:
security-
|
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
| Attachments: | test program | ||
Created attachment 2842 [details]
test program
Attached a test program. Sample run showing the problem:
$ /tmp/mt_lgamma -- -1
errno == EDOM
fetestexcept() says: FE_DIVBYZERO
lgamma(-1.00000000000000000e+00)=inf
EDOM FE_DIVBYZERO +inf
This bug appears to have been fixed in glibc 2.10, and man-pages-3.27 is updated accordingly. |
For the pole error, POSIX.1 says of lgamma(): Pole Error The x argument is a negative integer or zero. If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the divide-by-zero floating-point exception shall be raised. == glibc 2.8's lgamma() does raise the divide-by-zero exception, as expected. It also sets errno, but to the wrong value: errno is set to EDOM, when it should instead be ERANGE.