Add expansion of $variables in "let from query",

"if with query" and "while with query"

client/mysqltest.c

@@ -1328,6 +1328,7 @@ void var_query_set(VAR *var, const char *query, const char** query_end)
   MYSQL_RES *res;
   MYSQL_ROW row;
   MYSQL* mysql = &cur_con->mysql;
+  DYNAMIC_STRING ds_query;
   DBUG_ENTER("var_query_set");
   LINT_INIT(res);
 
@@ -1337,13 +1338,17 @@ void var_query_set(VAR *var, const char *query, const char** query_end)
     die("Syntax error in query, missing '`'");
   ++query;
 
-  if (mysql_real_query(mysql, query, (int)(end - query)) ||
+  /* Eval the query, thus replacing all environment variables */
+  init_dynamic_string(&ds_query, 0, (end - query) + 32, 256);
+  do_eval(&ds_query, query, end, FALSE);
+
+  if (mysql_real_query(mysql, ds_query.str, ds_query.length) ||
       !(res = mysql_store_result(mysql)))
   {
-    *end = 0;
-    die("Error running query '%s': %d %s", query,
+    die("Error running query '%s': %d %s", ds_query.str,
 	mysql_errno(mysql), mysql_error(mysql));
   }
+  dynstr_free(&ds_query);
 
   if ((row = mysql_fetch_row(res)) && row[0])
   {

mysql-test/r/mysqltest.result

@@ -268,6 +268,9 @@ mysqltest: At line 1: Missing assignment operator in let
 1
 # Execute: echo $success ;
 1 
+var2: content of variable 1
+var3: content of variable 1 content of variable 1
+length of var3 is longer than 0
 mysqltest: At line 1: Missing required argument 'filename' to command 'source'
 mysqltest: At line 1: Could not open file ./non_existingFile
 mysqltest: In included file "MYSQLTEST_VARDIR/tmp/recursive.sql": At line 1: Source directives are nesting too deep

mysql-test/t/mysqltest.test

@@ -685,6 +685,21 @@ echo # <whatever> success: $success ;
 --echo # Execute: echo \$success ;
 echo $success ;
 
+# ----------------------------------------------------------------------------
+# Test let from query with $variable
+# let $<var_name>=`<query with $variable>`;
+# ----------------------------------------------------------------------------
+
+let $var1=content of variable 1;
+let $var2= `select "$var1"`;
+let $var3= `select concat("$var1", " ", "$var2")`;
+echo var2: $var2;
+echo var3: $var3;
+if (`select length("$var3") > 0`)
+{
+  echo length of var3 is longer than 0;
+}
+
 # ----------------------------------------------------------------------------
 # Test to assign let from query
 # let $<var_name>=`<query>`;