snmptrapd: Let configure check for mysql_options()

Let configure check for mysql_options() instead of using mysql_options()
depending on the MySQL version. Only call load_defaults() or
my_load_defaults() if mysql_options() is not available. Parse not_argv[]
only if mysql_options() is not available. This last change fixes
Coverity ID 266336 ("logically dead code").

apps/snmptrapd_sql.c

@@ -421,9 +421,6 @@ netsnmp_mysql_connect(void)
 int
 netsnmp_mysql_init(void)
 {
-    int not_argc = 0, i;
-    char *not_args[] = { NULL };
-    char **not_argv = not_args;
     netsnmp_trapd_handler *traph;
 
     DEBUGMSGTL(("sql:init","called\n"));
@@ -450,14 +447,22 @@ netsnmp_mysql_init(void)
     my_init();
 #endif
 
+#if !defined(HAVE_MYSQL_OPTIONS)
+    {
+    int not_argc = 0, i;
+    char *not_args[] = { NULL };
+    char **not_argv = not_args;
+
     /** load .my.cnf values */
 #if HAVE_MY_LOAD_DEFAULTS
     my_load_defaults ("my", _sql.groups, &not_argc, &not_argv, 0);
 #elif defined(HAVE_LOAD_DEFAULTS)
     load_defaults ("my", _sql.groups, &not_argc, &not_argv);
+#else
+#error Neither load_defaults() nor mysql_options() are available.
 #endif
 
-    for(i=0; i < not_argc; ++i) {
+    for (i = 0; i < not_argc; ++i) {
         if (NULL == not_argv[i])
             continue;
         if (strncmp(not_argv[i],"--password=",11) == 0)
@@ -475,6 +480,8 @@ netsnmp_mysql_init(void)
         else
             snmp_log(LOG_WARNING, "unknown argument[%d] %s\n", i, not_argv[i]);
     }
+    }
+#endif /* !defined(HAVE_MYSQL_OPTIONS) */
 
     /** init bind structures */
     memset(_tbind, 0x0, sizeof(_tbind));
@@ -554,7 +561,7 @@ netsnmp_mysql_init(void)
         return -1;
     }
 
-#if MYSQL_VERSION_ID >= 100000
+#if HAVE_MYSQL_OPTIONS
     mysql_options(_sql.conn, MYSQL_READ_DEFAULT_GROUP, "snmptrapd");
 #endif
 

configure

@@ -24969,19 +24969,17 @@ $as_echo "no" >&6; }
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
-  ac_fn_c_check_func "$LINENO" "mysql_init" "ac_cv_func_mysql_init"
-if test "x$ac_cv_func_mysql_init" = xyes; then :
-
-$as_echo "#define HAVE_MYSQL_INIT 1" >>confdefs.h
-
-fi
-
-  ac_fn_c_check_func "$LINENO" "load_defaults" "ac_cv_func_load_defaults"
-if test "x$ac_cv_func_load_defaults" = xyes; then :
-
-$as_echo "#define HAVE_LOAD_DEFAULTS 1" >>confdefs.h
+  for ac_func in load_defaults mysql_init mysql_options
+do :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
 
 fi
+done
 
   CPPFLAGS="${_cppflags}"
   LIBS="${_libs}"

configure.d/config_os_libs2

@@ -553,14 +553,7 @@ if test "x$with_mysql" = "xyes" ; then
        AC_DEFINE([HAVE_MY_LOAD_DEFAULTS], 1,
                  [Define if having my_load_defaults()])],
       [AC_MSG_RESULT(no)])
-  AC_CHECK_FUNC(
-    [mysql_init],
-    AC_DEFINE([HAVE_MYSQL_INIT], 1,
-              [Define if mysql_init() is available in libmysqlclient]))
-  AC_CHECK_FUNC(
-    [load_defaults],
-    AC_DEFINE([HAVE_LOAD_DEFAULTS], 1,
-              [Define if load_defaults() is available in libmysqlclient]))
+  AC_CHECK_FUNCS([load_defaults mysql_init mysql_options])
   CPPFLAGS="${_cppflags}"
   LIBS="${_libs}"
   AC_MSG_CACHE_ADD(MYSQL Trap Logging:         enabled)

include/net-snmp/net-snmp-config.h.in

@@ -470,7 +470,7 @@
 /* Define to 1 if you have the <linux/tasks.h> header file. */
 #undef HAVE_LINUX_TASKS_H
 
-/* Define if load_defaults() is available in libmysqlclient */
+/* Define to 1 if you have the `load_defaults' function. */
 #undef HAVE_LOAD_DEFAULTS
 
 /* Define to 1 if you have the <locale.h> header file. */
@@ -521,9 +521,12 @@
 /* Define to 1 if you have the <mtab.h> header file. */
 #undef HAVE_MTAB_H
 
-/* Define if mysql_init() is available in libmysqlclient */
+/* Define to 1 if you have the `mysql_init' function. */
 #undef HAVE_MYSQL_INIT
 
+/* Define to 1 if you have the `mysql_options' function. */
+#undef HAVE_MYSQL_OPTIONS
+
 /* Define to 1 if you have the <my_global.h> header file. */
 #undef HAVE_MY_GLOBAL_H