Revisit PR #840

ext/mysql2/client.c

@@ -114,7 +114,7 @@ static VALUE rb_set_ssl_mode_option(VALUE self, VALUE setting) {
   int val = NUM2INT( setting );
   if (version >= 50703 && version < 50711) {
     if (val == SSL_MODE_DISABLED || val == SSL_MODE_REQUIRED) {
-      bool b = ( val == SSL_MODE_REQUIRED );
+      my_bool b = ( val == SSL_MODE_REQUIRED );
       int result = mysql_options( wrapper->client, MYSQL_OPT_SSL_ENFORCE, &b );
       return INT2NUM(result);
     } else {
@@ -526,7 +526,7 @@ static VALUE do_send_query(void *args) {
  */
 static void *nogvl_read_query_result(void *ptr) {
   MYSQL * client = ptr;
-  bool res = mysql_read_query_result(client);
+  my_bool res = mysql_read_query_result(client);
 
   return (void *)(res == 0 ? Qtrue : Qfalse);
 }
@@ -846,7 +846,7 @@ static VALUE _mysql_client_options(VALUE self, int opt, VALUE value) {
   const void *retval = NULL;
   unsigned int intval = 0;
   const char * charval = NULL;
-  bool boolval;
+  my_bool boolval;
 
   GET_CLIENT(self);
 

ext/mysql2/extconf.rb

@@ -105,12 +105,17 @@ def add_ssl_defines(header)
 add_ssl_defines(mysql_h)
 have_struct_member('MYSQL', 'net.vio', mysql_h)
 have_struct_member('MYSQL', 'net.pvio', mysql_h)
+
 # These constants are actually enums, so they cannot be detected by #ifdef in C code.
 have_const('MYSQL_ENABLE_CLEARTEXT_PLUGIN', mysql_h)
 have_const('SERVER_QUERY_NO_GOOD_INDEX_USED', mysql_h)
 have_const('SERVER_QUERY_NO_INDEX_USED', mysql_h)
 have_const('SERVER_QUERY_WAS_SLOW', mysql_h)
 
+# my_bool is replaced by C99 bool in MySQL 8.0, but we want
+# to retain compatibility with the typedef in earlier MySQLs.
+have_type('my_bool', mysql_h)
+
 # This is our wishlist. We use whichever flags work on the host.
 # -Wall and -Wextra are included by default.
 wishlist = [

ext/mysql2/mysql2_ext.h

@@ -28,6 +28,14 @@ void Init_mysql2(void);
 #define RB_MYSQL_UNUSED
 #endif
 
+/* MySQL 8.0 replaces my_bool with C99 bool. Earlier versions of MySQL had
+ * a typedef to char. Gem users reported failures on big endian systems when
+ * using C99 bool types with older MySQLs due to mismatched behavior. */
+#ifndef HAVE_TYPE_MY_BOOL
+#include <stdbool.h>
+typedef bool my_bool;
+#endif
+
 #include <client.h>
 #include <statement.h>
 #include <result.h>

ext/mysql2/result.c

@@ -218,8 +218,8 @@ static void rb_mysql_result_alloc_result_buffers(VALUE self, MYSQL_FIELD *fields
   if (wrapper->result_buffers != NULL) return;
 
   wrapper->result_buffers = xcalloc(wrapper->numberOfFields, sizeof(MYSQL_BIND));
-  wrapper->is_null = xcalloc(wrapper->numberOfFields, sizeof(bool));
-  wrapper->error = xcalloc(wrapper->numberOfFields, sizeof(bool));
+  wrapper->is_null = xcalloc(wrapper->numberOfFields, sizeof(my_bool));
+  wrapper->error = xcalloc(wrapper->numberOfFields, sizeof(my_bool));
   wrapper->length = xcalloc(wrapper->numberOfFields, sizeof(unsigned long));
 
   for (i = 0; i < wrapper->numberOfFields; i++) {

ext/mysql2/result.h

@@ -1,6 +1,5 @@
 #ifndef MYSQL2_RESULT_H
 #define MYSQL2_RESULT_H
-#include <stdbool.h>
 
 void init_mysql2_result(void);
 VALUE rb_mysql_result_to_obj(VALUE client, VALUE encoding, VALUE options, MYSQL_RES *r, VALUE statement);
@@ -22,8 +21,8 @@ typedef struct {
   mysql_client_wrapper *client_wrapper;
   /* statement result bind buffers */
   MYSQL_BIND *result_buffers;
-  bool *is_null;
-  bool *error;
+  my_bool *is_null;
+  my_bool *error;
   unsigned long *length;
 } mysql2_result_wrapper;
 

ext/mysql2/statement.c

@@ -115,7 +115,7 @@ VALUE rb_mysql_stmt_new(VALUE rb_client, VALUE sql) {
 
   // set STMT_ATTR_UPDATE_MAX_LENGTH attr
   {
-    bool truth = 1;
+    my_bool truth = 1;
     if (mysql_stmt_attr_set(stmt_wrapper->stmt, STMT_ATTR_UPDATE_MAX_LENGTH, &truth)) {
       rb_raise(cMysql2Error, "Unable to initialize prepared statement: set STMT_ATTR_UPDATE_MAX_LENGTH");
     }