A fix and test case for Bug#7990 "mysql_stmt_close doesn't

reset mysql->net.last_error": the solution is to clear
MYSQL->net error before performing COM_CLOSE: if the call
succeeds, the connection is usable for other statements.
More comprehensive fix is to clear MYSQL->net for all
recoverable errors at the time they happen, it will be
implemented in 5.0 as it introduces incompatibility in behavior.


libmysql/libmysql.c:
  A simple fix for Bug#7990 "mysql_stmt_close doesn't reset 
  mysql->net.last_error"
tests/mysql_client_test.c:
  A test case for Bug#7990 " mysql_stmt_close doesn't reset 
  mysql->net.last_error"

1 files changed, 17 insertions, 0 deletions

diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index 24a7fa5f929..76cf5c3913c 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -1788,6 +1788,18 @@ static my_bool my_realloc_str(NET *net, ulong length)
 }
 
 
+/* Clear possible error statee of struct NET */
+
+static void net_clear_error(NET *net)
+{
+  if (net->last_errno)
+  {
+    net->last_errno= 0;
+    net->last_error[0]= '\0';
+    strmov(net->sqlstate, not_error_sqlstate);
+  }
+}
+
 /*
   Set statement error code, sqlstate, and error message
   from given errcode and sqlstate.
@@ -4512,6 +4524,11 @@ my_bool STDCALL mysql_stmt_close(MYSQL_STMT *stmt)
 
       if (mysql->unbuffered_fetch_owner == &stmt->unbuffered_fetch_cancelled)
         mysql->unbuffered_fetch_owner= 0;
+      /*
+        Clear NET error state: if the following commands come through
+        successfully, connection will still be usable for other commands.
+      */
+      net_clear_error(&mysql->net);
       if (mysql->status != MYSQL_STATUS_READY)
       {
         /*