bk commit into 4.1 tree (msvensson:1.2472) BUG#15869

[msvensson]

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ChangeSet
  1.2472 06/05/18 17:39:01 msvensson@neptunus.(none) +2 -0
  Bug#15869  Cannot shutdown the server - it restarts
   - A segfault occured when the function 'kill_server' called 
     'my_sigset' with signal number 0. 'my_sigset' is a macro which
     uses 'sigaction' to install the signal handler with an invalid
     signal number will on most platforms return EINVAL but yields
     a segfauilt on IRIX 6.5
   - The server crash was detected by mysqld_safe and it was restarted although
     a shutdown was requested. 

  sql/mysqld.cc
    1.612 06/05/18 17:38:58 msvensson@neptunus.(none) +2 -1
    Don't call my_sigset if signo is 0 

  include/my_pthread.h
    1.82 06/05/18 17:38:58 msvensson@neptunus.(none) +4 -2
    Check return value from sigaction with a DBUG_ASSERT
    Also DBUG_ASSERT if signla number 0 is passed

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	msvensson
# Host:	neptunus.(none)
# Root:	/home/msvensson/mysql/my41-bug13711

--- 1.81/include/my_pthread.h	2005-10-11 18:12:09 +02:00
+++ 1.82/include/my_pthread.h	2006-05-18 17:38:58 +02:00
@@ -329,12 +329,14 @@
   we want to make sure that no such flags are set.
 */
 #if defined(HAVE_SIGACTION) && !defined(my_sigset)
-#define my_sigset(A,B) do { struct sigaction s; sigset_t set;              \
+#define my_sigset(A,B) do { struct sigaction s; sigset_t set; int rc;      \
+                            DBUG_ASSERT((A) != 0);                         \
                             sigemptyset(&set);                             \
                             s.sa_handler = (B);                            \
                             s.sa_mask    = set;                            \
                             s.sa_flags   = 0;                              \
-                            sigaction((A), &s, (struct sigaction *) NULL); \
+                            rc= sigaction((A), &s, (struct sigaction *) NULL);\
+                            DBUG_ASSERT(rc == 0);                          \
                           } while (0)
 #elif defined(HAVE_SIGSET) && !defined(my_sigset)
 #define my_sigset(A,B) sigset((A),(B))

--- 1.611/sql/mysqld.cc	2006-04-13 12:06:37 +02:00
+++ 1.612/sql/mysqld.cc	2006-05-18 17:38:58 +02:00
@@ -884,7 +884,8 @@
     RETURN_FROM_KILL_SERVER;
   kill_in_progress=TRUE;
   abort_loop=1;					// This should be set
-  my_sigset(sig,SIG_IGN);
+  if (sig != 0) // 0 is not a valid signal number
+    my_sigset(sig,SIG_IGN);
   if (sig == MYSQL_KILL_SIGNAL || sig == 0)
     sql_print_information(ER(ER_NORMAL_SHUTDOWN),my_progname);
   else