bk commit into 5.0 tree (cmiller:1.2228) BUG#20908

[Chad MILLER]

Below is the list of changes that have just been committed into a local
5.0 repository of cmiller. When cmiller does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2006-08-15 00:33:51+02:00, cmiller@stripped +3 -0
  Bug #20908: Crash if select @@""
  
  Zero-length variables caused failures when using the length to look
  up the name in a hash.  Instead, signal that no zero-length name can
  ever be found.

  mysql-test/r/variables.result@stripped, 2006-08-15 00:29:15+02:00, cmiller@stripped
+6 -0
    Results for test.

  mysql-test/t/variables.test@stripped, 2006-08-15 00:29:15+02:00, cmiller@stripped
+11 -0
    Insert tests to prove that zero-length variable names do not cause
    faults.

  sql/gen_lex_hash.cc@stripped, 2006-08-15 00:29:16+02:00, cmiller@stripped +4 -0
    If the length is zero, then there is nothing to look-up in the 
    hash.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	cmiller
# Host:	maint1.mysql.com
# Root:	/data/localhome/cmiller/bug20908/my50-bug20908

--- 1.66/sql/gen_lex_hash.cc	2006-08-15 00:34:16 +02:00
+++ 1.67/sql/gen_lex_hash.cc	2006-08-15 00:34:16 +02:00
@@ -468,6 +468,10 @@ static inline SYMBOL *get_hash_symbol(co
 {\n\
   register uchar *hash_map;\n\
   register const char *cur_str= s;\n\
+\n\
+  if (len == 0)\n\
+    return(NULL);\n\
+\n\
   if (function){\n\
     if (len>sql_functions_max_len) return 0;\n\
     hash_map= sql_functions_map;\n\

--- 1.87/mysql-test/r/variables.result	2006-08-15 00:34:16 +02:00
+++ 1.88/mysql-test/r/variables.result	2006-08-15 00:34:16 +02:00
@@ -689,6 +689,12 @@ select @@log_queries_not_using_indexes;
 show variables like 'log_queries_not_using_indexes';
 Variable_name	Value
 log_queries_not_using_indexes	OFF
+select @@"";
+ERROR HY000: Unknown system variable ''
+select @@&;
+ERROR HY000: Unknown system variable ''
+select @@@;
+ERROR HY000: Unknown system variable ''
 End of 5.0 tests
 set global binlog_cache_size         =@my_binlog_cache_size;
 set global connect_timeout           =@my_connect_timeout;

--- 1.62/mysql-test/t/variables.test	2006-08-15 00:34:16 +02:00
+++ 1.63/mysql-test/t/variables.test	2006-08-15 00:34:16 +02:00
@@ -585,6 +585,16 @@ show variables like 'ssl%';
 select @@log_queries_not_using_indexes;
 show variables like 'log_queries_not_using_indexes';
 
+#
+# Bug#20908: Crash if select @@""
+#
+--error 1193
+select @@"";
+--error 1193
+select @@&;
+--error 1193
+select @@@;
+
 --echo End of 5.0 tests
 
 # This is at the very after the versioned tests, since it involves doing
@@ -620,3 +630,4 @@ set global server_id                 =@m
 set global slow_launch_time          =@my_slow_launch_time;
 set global storage_engine            =@my_storage_engine;
 set global thread_cache_size         =@my_thread_cache_size;
+