From f9832bf116b2525afa79267cfea6cd8360e418f6 Mon Sep 17 00:00:00 2001 From: unknown Date: Wed, 23 Aug 2006 19:14:58 +0200 Subject: 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 and that to encounter one is a syntax error. mysql-test/r/variables.result: Results for test. mysql-test/t/variables.test: Insert tests to prove that zero-length variable names do not cause faults. sql/gen_lex_hash.cc: If the length is zero, then there is nothing to look-up in the hash. sql/sql_lex.cc: Names of variables must not be empty. Signal an error of that happens. --- sql/gen_lex_hash.cc | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'sql/gen_lex_hash.cc') diff --git a/sql/gen_lex_hash.cc b/sql/gen_lex_hash.cc index 7e0b178f7af..89af0d30076 100644 --- a/sql/gen_lex_hash.cc +++ b/sql/gen_lex_hash.cc @@ -447,8 +447,9 @@ int main(int argc,char **argv) and you are welcome to modify and redistribute it under the GPL license\n\ \n*/\n\n"); - printf("/* This code is generated by gen_lex_hash.cc that seeks for\ - a perfect\nhash function */\n\n"); + /* Broken up to indicate that it's not advice to you, gentle reader. */ + printf("/* Do " "not " "edit " "this " "file! This is generated by " + "gen_lex_hash.cc\nthat seeks for a perfect hash function */\n\n"); printf("#include \"lex.h\"\n\n"); calc_length(); @@ -468,6 +469,12 @@ static inline SYMBOL *get_hash_symbol(const char *s,\n\ {\n\ register uchar *hash_map;\n\ register const char *cur_str= s;\n\ +\n\ + if (len == 0) {\n\ + DBUG_PRINT(\"warning\", (\"get_hash_symbol() received a request for a zero-length symbol, which is probably a mistake.\"));\ + return(NULL);\n\ + }\ +\n\ if (function){\n\ if (len>sql_functions_max_len) return 0;\n\ hash_map= sql_functions_map;\n\ -- cgit v1.2.1