Bug#32757: hang with sql_mode set when setting some global variables

If setting a system-variable provided by a plug-in failed, no OK or
error was sent in some cases, hanging the client. We now send an error
in the case from the ticket (integer-argument out of range in STRICT
mode). We also provide a semi-generic fallback message for possible
future cases like this where an error is signalled, but no message is
sent to the client. The error/warning handling is unified so it's the
same again for variables provided by plugins and those in the server
proper.


mysql-test/r/plugin.result:
  show that on out-of-range values, plugin interface throws errors
  in STRICT mode and warnings otherwise.
mysql-test/t/plugin.test:
  show that on out-of-range values, plugin interface throws errors
  in STRICT mode and warnings otherwise.
sql/set_var.cc:
  - handle signedness of values used in warnings
  - in STRICT mode, throw errors rather than warnings
sql/sql_parse.cc:
  If sql_set_variables() returns with an error but no message
  was sent to the client, send a semi-generic one so the session
  won't hang and we won't fail silently.
sql/sql_plugin.cc:
  throw a warning if more than just block-size was corrected
  (or an error in STRICT mode). use functions from set_var
  for uniform behaviour of server- and plug-in variables.
storage/example/ha_example.cc:
  Add a ULONG system variable to example plugin so
  we can test integers in the plugin-interface without
  having to depend on the presence of innobase.

1 files changed, 8 insertions, 31 deletions

diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 2a86844c8c6..5fafa751379 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -210,6 +210,8 @@ static void reap_plugins(void);
 
 /* declared in set_var.cc */
 extern sys_var *intern_find_sys_var(const char *str, uint length, bool no_error);
+extern bool throw_bounds_warning(THD *thd, bool fixed, bool unsignd,
+                                 const char *name, longlong val);
 
 #ifdef EMBEDDED_LIBRARY
 /* declared in sql_base.cc */
@@ -1888,16 +1890,8 @@ static int check_func_int(THD *thd, struct st_mysql_sys_var *var,
   else
     *(int *)save= (int) getopt_ll_limit_value(tmp, &options, &fixed);
 
-  if (fixed)
-  {
-    char buf[22];
-    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
-                        ER_TRUNCATED_WRONG_VALUE,
-                        ER(ER_TRUNCATED_WRONG_VALUE), var->name,
-                        ullstr(tmp, buf));
-  }
-  return (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES) &&
-         (*(int *)save != (int) tmp);
+  return throw_bounds_warning(thd, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
+                              var->name, (longlong) tmp);
 }
 
 
@@ -1916,16 +1910,8 @@ static int check_func_long(THD *thd, struct st_mysql_sys_var *var,
   else
     *(long *)save= (long) getopt_ll_limit_value(tmp, &options, &fixed);
 
-  if (fixed)
-  {
-    char buf[22];
-    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
-                        ER_TRUNCATED_WRONG_VALUE,
-                        ER(ER_TRUNCATED_WRONG_VALUE), var->name,
-                        ullstr(tmp, buf));
-  }
-  return (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES) &&
-         (*(long *)save != (long) tmp);
+  return throw_bounds_warning(thd, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
+                              var->name, (longlong) tmp);
 }
 
 
@@ -1937,7 +1923,6 @@ static int check_func_longlong(THD *thd, struct st_mysql_sys_var *var,
   struct my_option options;
   value->val_int(value, &tmp);
   plugin_opt_set_limits(&options, var);
-  *(ulonglong *)save= getopt_ull_limit_value(tmp, &options, &fixed);
 
   if (var->flags & PLUGIN_VAR_UNSIGNED)
     *(ulonglong *)save= getopt_ull_limit_value((ulonglong) tmp, &options,
@@ -1945,16 +1930,8 @@ static int check_func_longlong(THD *thd, struct st_mysql_sys_var *var,
   else
     *(longlong *)save= getopt_ll_limit_value(tmp, &options, &fixed);
 
-  if (fixed)
-  {
-    char buf[22];
-    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
-                        ER_TRUNCATED_WRONG_VALUE,
-                        ER(ER_TRUNCATED_WRONG_VALUE), var->name,
-                        ullstr(tmp, buf));
-  }
-  return (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES) &&
-         (*(long long *)save != tmp);
+  return throw_bounds_warning(thd, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
+                              var->name, (longlong) tmp);
 }
 
 static int check_func_str(THD *thd, struct st_mysql_sys_var *var,