cleanup: invert return code

sql/sql_class.cc

@@ -213,11 +213,11 @@ Foreign_key::Foreign_key(const Foreign_key &rhs, MEM_ROOT *mem_root)
     We only compare field names
 
   RETURN
-    0	Generated key is a prefix of other key
-    1	Not equal
+    true        Generated key is a prefix of other key
+    false       Not a prefix
 */
 
-bool foreign_key_prefix(Key *a, Key *b)
+bool is_foreign_key_prefix(Key *a, Key *b)
 {
   /* Ensure that 'a' is the generated key */
   if (a->generated)
@@ -228,13 +228,13 @@ bool foreign_key_prefix(Key *a, Key *b)
   else
   {
     if (!b->generated)
-      return TRUE;                              // No foreign key
+      return false;                             // No foreign key
     swap_variables(Key*, a, b);                 // Put generated key in 'a'
   }
 
   /* Test if 'a' is a prefix of 'b' */
   if (a->columns.elements > b->columns.elements)
-    return TRUE;                                // Can't be prefix
+    return false;                                // Can't be prefix
 
   List_iterator<Key_part_spec> col_it1(a->columns);
   List_iterator<Key_part_spec> col_it2(b->columns);
@@ -254,17 +254,17 @@ bool foreign_key_prefix(Key *a, Key *b)
       }
     }
     if (!found)
-      return TRUE;                              // Error
+      return false;                             // Error
   }
-  return FALSE;                                 // Is prefix
+  return true;                                  // Is prefix
 #else
   while ((col1= col_it1++))
   {
     col2= col_it2++;
     if (!(*col1 == *col2))
-      return TRUE;
+      return false;
   }
-  return FALSE;                                 // Is prefix
+  return true;                                 // Is prefix
 #endif
 }
 

sql/sql_class.h

@@ -446,7 +446,7 @@ class Key :public Sql_alloc, public DDL_options {
   Key(const Key &rhs, MEM_ROOT *mem_root);
   virtual ~Key() = default;
   /* Equality comparison of keys (ignoring name) */
-  friend bool foreign_key_prefix(Key *a, Key *b);
+  friend bool is_foreign_key_prefix(Key *a, Key *b);
   /**
     Used to make a clone of this object for ALTER/CREATE TABLE
     @sa comment for Key_part_spec::clone

sql/sql_table.cc

@@ -3835,13 +3835,12 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
       while ((key2 = key_iterator2++) != key)
       {
 	/*
-          foreign_key_prefix(key, key2) returns 0 if key or key2, or both, is
-          'generated', and a generated key is a prefix of the other key.
-          Then we do not need the generated shorter key.
+          is_foreign_key_prefix(key, key2) returns true if key or key2, or
+          both, is 'generated', and a generated key is a prefix of the other
+          key. Then we do not need the generated shorter key.
         */
-        if ((key2->type != Key::FOREIGN_KEY &&
-             key2->name.str != ignore_key &&
-             !foreign_key_prefix(key, key2)))
+        if (key2->type != Key::FOREIGN_KEY && key2->name.str != ignore_key &&
+            is_foreign_key_prefix(key, key2))
         {
           /* mark that the generated key should be ignored */
           if (!key2->generated ||