From 23241eb2d31ea1337c425401b6ae542586c4b5fa Mon Sep 17 00:00:00 2001
From: dimitr <dimitr@users.sourceforge.net>
Date: Thu, 14 Jul 2011 15:54:27 +0000
Subject: [PATCH] Front ported CORE-3554: Server crashes during prepare or
 throws incorrect parsing error if the remotely passed SQL query is empty.

---
 src/dsql/dsql.cpp        | 36 +++++++++---------------------------
 src/remote/interface.cpp | 20 ++++++++++++++++++--
 src/remote/protocol.cpp  |  7 +++++++
 3 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/src/dsql/dsql.cpp b/src/dsql/dsql.cpp
index ded72d7b4d..69003161ce 100644
--- a/src/dsql/dsql.cpp
+++ b/src/dsql/dsql.cpp
@@ -682,17 +682,6 @@ void DSQL_prepare(thread_db* tdbb,
 
 	dsql_req* request = NULL;
 
-	if (!string) {
-		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
-				  // Unexpected end of command
-				  // CVC: Nothing will be line 1, column 1 for the user.
-				  Arg::Gds(isc_command_end_err2) << Arg::Num(1) << Arg::Num(1));
-	}
-
-	if (!length) {
-		length = strlen(string);
-	}
-
 	try {
 
 		// Figure out which parser version to use
@@ -1098,17 +1087,6 @@ static void execute_immediate(thread_db* tdbb,
 {
 	SET_TDBB(tdbb);
 
-	if (!string) {
-		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
-				  // Unexpected end of command
-				  // CVC: Nothing will be line 1, column 1 for the user.
-				  Arg::Gds(isc_command_end_err2) << Arg::Num(1) << Arg::Num(1));
-	}
-
-	if (!length) {
-		length = strlen(string);
-	}
-
 	dsql_dbb* const database = init(attachment);
 	dsql_req* request = NULL;
 
@@ -2558,17 +2536,21 @@ static dsql_req* prepare(thread_db* tdbb, dsql_dbb* database, jrd_tra* transacti
 				  Arg::Gds(isc_wish_list));
 	}
 
-	if (!string) {
+	if (string && !string_length)
+	{
+		size_t sql_length = strlen(string);
+		if (sql_length > MAX_USHORT)
+			sql_length = MAX_USHORT;
+		string_length = static_cast<USHORT>(sql_length);
+	}
+
+	if (!string || !string_length) {
 		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
 				  // Unexpected end of command
 				  // CVC: Nothing will be line 1, column 1 for the user.
 				  Arg::Gds(isc_command_end_err2) << Arg::Num(1) << Arg::Num(1));
 	}
 
-	if (!string_length) {
-		string_length = strlen(string);
-	}
-
 	// Get rid of the trailing ";" if there is one.
 
 	for (const TEXT* p = string + string_length; p-- > string;)
diff --git a/src/remote/interface.cpp b/src/remote/interface.cpp
index bc1648f8ea..f8b091c28c 100644
--- a/src/remote/interface.cpp
+++ b/src/remote/interface.cpp
@@ -1496,6 +1496,14 @@ ISC_STATUS GDS_DSQL_EXECUTE_IMMED2(ISC_STATUS* user_status,
 
 	rdb->set_status_vector(user_status);
 
+	if (!length)
+	{
+		size_t sql_length = strlen(string);
+		if (sql_length > MAX_USHORT)
+			sql_length = MAX_USHORT;
+		length = static_cast<USHORT>(sql_length);
+	}
+
 	if (dialect > 10)
 	{
 		// dimitr: adjust dialect received after
@@ -1588,7 +1596,7 @@ ISC_STATUS GDS_DSQL_EXECUTE_IMMED2(ISC_STATUS* user_status,
 		P_SQLST* ex_now = &packet->p_sqlst;
 		ex_now->p_sqlst_transaction = transaction ? transaction->rtr_id : 0;
 		ex_now->p_sqlst_SQL_dialect = dialect;
-		ex_now->p_sqlst_SQL_str.cstr_length = length ? length : strlen(string);
+		ex_now->p_sqlst_SQL_str.cstr_length = length;
 		ex_now->p_sqlst_SQL_str.cstr_address = reinterpret_cast<const UCHAR*>(string);
 		ex_now->p_sqlst_items.cstr_length = 0;
 		ex_now->p_sqlst_buffer_length = 0;
@@ -2181,6 +2189,14 @@ ISC_STATUS GDS_DSQL_PREPARE(ISC_STATUS* user_status, Rtr** rtr_handle,
 	}
 	rdb->set_status_vector(user_status);
 
+	if (!length)
+	{
+		size_t sql_length = strlen(string);
+		if (sql_length > MAX_USHORT)
+			sql_length = MAX_USHORT;
+		length = static_cast<USHORT>(sql_length);
+	}
+
 	if (dialect > 10)
 	{
 		// dimitr: adjust dialect received after
@@ -2223,7 +2239,7 @@ ISC_STATUS GDS_DSQL_PREPARE(ISC_STATUS* user_status, Rtr** rtr_handle,
 		prepare->p_sqlst_transaction = transaction ? transaction->rtr_id : 0;
 		prepare->p_sqlst_statement = statement->rsr_id;
 		prepare->p_sqlst_SQL_dialect = dialect;
-		prepare->p_sqlst_SQL_str.cstr_length = length ? length : strlen(string);
+		prepare->p_sqlst_SQL_str.cstr_length = length;
 		prepare->p_sqlst_SQL_str.cstr_address = reinterpret_cast<const UCHAR*>(string);
 		prepare->p_sqlst_items.cstr_length = item_length;
 		prepare->p_sqlst_items.cstr_address = items;
diff --git a/src/remote/protocol.cpp b/src/remote/protocol.cpp
index 3d6aceb262..84dd20e065 100644
--- a/src/remote/protocol.cpp
+++ b/src/remote/protocol.cpp
@@ -848,7 +848,14 @@ static bool alloc_cstring(XDR* xdrs, CSTRING* cstring)
  **************************************/
 
 	if (!cstring->cstr_length)
+	{
+		if (cstring->cstr_allocated)
+			*cstring->cstr_address = '\0';
+		else
+			cstring->cstr_address = NULL;
+
 		return true;
+	}
 
 	if (cstring->cstr_length > cstring->cstr_allocated && cstring->cstr_allocated)
 	{