Fix to get core file on Linux

Docs/manual.texi:
  ChangeLog
sql/mysqld.cc:
  Write info about writing core file to stderr

BUILD/compile-pentium-valgrind-max

+#! /bin/sh
+
+path=`dirname $0`
+. "$path/SETUP.sh"
+
+extra_flags="$pentium_cflags $debug_cflags -DHAVE_purify"
+c_warnings="$c_warnings $debug_extra_warnings"
+cxx_warnings="$cxx_warnings $debug_extra_warnings"
+extra_configs="$pentium_configs $debug_configs"
+
+extra_configs="$extra_configs"
+
+. "$path/FINISH.sh"

Docs/manual.texi

@@ -46930,6 +46930,8 @@ not yet 100% confident in this code.
 @appendixsubsec Changes in release 3.23.54
 @itemize
 @item
+Fixed that @code{--core-file} works on Linux (at least on kernel 2.4.18).
+@item
 Fixed a problem with BDB and @code{ALTER TABLE}.
 @item
 Fixed reference to freed memory when doing complicated @code{GROUP BY

sql/mysqld.cc

@@ -1326,7 +1326,11 @@ information that should help you find out what is causing the crash\n");
 #endif /* HAVE_STACKTRACE */
 
  if (test_flags & TEST_CORE_ON_SIGNAL)
+ {
+   fprintf(stderr, "Writing a core file\n");
+   fflush(stderr);
    write_core(sig);
+ }
  exit(1);
 }
 

sql/stacktrace.c

@@ -206,7 +206,7 @@ resolve it\n");
 
 /* Produce a core for the thread */
 
-#ifdef HAVE_LINUXTHREADS
+#ifdef NOT_USED /* HAVE_LINUXTHREADS */
 void write_core(int sig)
 {
   signal(sig, SIG_DFL);