[Freeipa-devel] [freeipa PR#6085][opened] Fix use of comparison functions to avoid GCC bug 95189

[abbra]

   URL: https://github.com/freeipa/freeipa/pull/6085
Author: abbra
 Title: #6085: Fix use of comparison functions to avoid GCC bug 95189
Action: opened

PR body:
"""
Due to a bug in GCC 9 and GCC 10 optimizing code, all C library
comparison functions should be used with explicit result comparison in
the code to avoid problems described in

http://r6.ca/blog/20200929T023701Z.html

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95189

The code below is affected:

```
    if (strcmp(a, b) || !strcmp(c, d)) ...
```

while the code below is not affected:

```
    if (strcmp(a, b) != 0 || strcmp(c, d)) == 0
```

for all C library cmp functions and related:

 - strcmp(), strncmp()
 - strcasecmp(), strncasecmp()
 - stricmp(), strnicmp()
 - memcmp()

This PR idea is based on the pull request by 'Nicolas Williams
<nico(a)twosigma.com&gt;&#39;
to Heimdal Kerberos: https://github.com/heimdal/heimdal/pull/855

Signed-off-by: Alexander Bokovoy <abokovoy(a)redhat.com&gt;
"""

To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/6085/head:pr6085
git checkout pr6085