Bug#20145 perror segfault when call it with error nr

  - Add test case(execute perror)
  - Check if strerror has returned NULL and set msg to "Unknown Error" in that case
  - Thanks to Steven Xie for pointing out how to fix. 


extra/perror.c:
  strerror might return NULL on Solaris 2.8
mysql-test/mysql-test-run.pl:
  Add possibility to execute perror from test case
mysql-test/r/have_perror.require:
  New BitKeeper file ``mysql-test/r/have_perror.require''
mysql-test/r/perror.result:
  New BitKeeper file ``mysql-test/r/perror.result''
mysql-test/t/perror.test:
  New BitKeeper file ``mysql-test/t/perror.test''

1 files changed, 4 insertions, 1 deletions

diff --git a/extra/perror.c b/extra/perror.c
index 82311c1b2c9..531d30dae86 100644
--- a/extra/perror.c
+++ b/extra/perror.c
@@ -218,8 +218,11 @@ int main(int argc,char *argv[])
       On some system, like NETWARE, strerror(unknown_error) returns a
       string 'Unknown Error'.  To avoid printing it we try to find the
       error string by asking for an impossible big error message.
+
+      On Solaris 2.8 it might return NULL
     */
-    msg= strerror(10000);
+    if ((msg= strerror(10000)) == NULL)
+      msg= "Unknown Error";
 
     /*
       Allocate a buffer for unknown_error since strerror always returns