Fixed #8027: Broken gbak statistics

(cherry picked from commit 210310eab3)

src/remote/client/interface.cpp

@@ -128,10 +128,10 @@ namespace {
 			status_exception::raise(Arg::Gds(isc_imp_exc) << Arg::Gds(isc_blktoobig));
 	}
 
-	class SaveString
+	class UsePreallocatedBuffer
 	{
 	public:
-		SaveString(cstring& toSave, ULONG newLength, UCHAR* newBuffer)
+		UsePreallocatedBuffer(cstring& toSave, ULONG newLength, UCHAR* newBuffer)
 			: ptr(&toSave),
 			  oldValue(*ptr)
 		{
@@ -139,16 +139,30 @@ namespace {
 			ptr->cstr_allocated = newLength;
 		}
 
-		~SaveString()
+		~UsePreallocatedBuffer()
 		{
 			*ptr = oldValue;
 		}
 
-	private:
+	protected:
 		cstring* ptr;
+	private:
 		cstring oldValue;
 	};
 
+	class UseStandardBuffer : public UsePreallocatedBuffer
+	{
+	public:
+		UseStandardBuffer(cstring& toSave)
+			: UsePreallocatedBuffer(toSave,0, nullptr)
+		{ }
+
+		~UseStandardBuffer()
+		{
+			ptr->free();
+		}
+	};
+
 	class ClientPortsCleanup : public PortsCleanup
 	{
 	public:
@@ -4146,7 +4160,7 @@ Statement* Attachment::prepare(CheckStatusWrapper* status, ITransaction* apiTra,
 		}
 
 		P_RESP* response = &packet->p_resp;
-		SaveString temp(response->p_resp_data, buffer.getCount(), buffer.begin());
+		UsePreallocatedBuffer temp(response->p_resp_data, buffer.getCount(), buffer.begin());
 
 		try
 		{
@@ -5064,7 +5078,7 @@ int Blob::getSegment(CheckStatusWrapper* status, unsigned int bufferLength, void
 		PACKET* packet = &rdb->rdb_packet;
 		P_SGMT* segment = &packet->p_sgmt;
 		P_RESP* response = &packet->p_resp;
-		SaveString temp(response->p_resp_data, bufferLength, bufferPtr);
+		UsePreallocatedBuffer temp(response->p_resp_data, bufferLength, bufferPtr);
 
 		// Handle a blob that has been created rather than opened (this should yield an error)
 
@@ -7366,6 +7380,9 @@ static void batch_dsql_fetch(rem_port*	port,
 	// we need to clear the queue
 	const bool clear_queue = (id != statement->rsr_id || port->port_type == rem_port::XNET);
 
+	// Avoid damaging preallocated buffer for response data
+	UseStandardBuffer guard(packet->p_resp.p_resp_data);
+
 	statement->rsr_flags.set(Rsr::FETCHED);
 	while (true)
 	{
@@ -7511,6 +7528,9 @@ static void batch_gds_receive(rem_port*		port,
 		clear_queue = true;
 	}
 
+	// Avoid damaging preallocated buffer for response data
+	UseStandardBuffer guard(packet->p_resp.p_resp_data);
+
 	// Receive the whole batch of records, until end-of-batch is seen
 
 	while (true)
@@ -7928,7 +7948,7 @@ static void info(CheckStatusWrapper* status,
 	// Set up for the response packet.
 
 	P_RESP* response = &packet->p_resp;
-	SaveString temp(response->p_resp_data, buffer_length, buffer);
+	UsePreallocatedBuffer temp(response->p_resp_data, buffer_length, buffer);
 
 	receive_response(status, rdb, packet);
 }
@@ -9138,8 +9158,7 @@ static void svcstart(CheckStatusWrapper*	status,
 
 	// Set up for the response packet.
 	P_RESP* response = &packet->p_resp;
-	SaveString temp(response->p_resp_data, 0, NULL);
-	response->p_resp_data.cstr_length = 0;
+	UseStandardBuffer temp(response->p_resp_data);
 
 	receive_response(status, rdb, packet);
 }

src/remote/protocol.cpp

@@ -100,7 +100,6 @@ enum SQL_STMT_TYPE
 };
 
 static bool alloc_cstring(RemoteXdr*, CSTRING*);
-static void free_cstring(RemoteXdr*, CSTRING*);
 static void reset_statement(RemoteXdr*, SSHORT);
 static bool_t xdr_cstring(RemoteXdr*, CSTRING*);
 static bool_t xdr_response(RemoteXdr*, CSTRING*);
@@ -1242,7 +1241,7 @@ static bool alloc_cstring(RemoteXdr* xdrs, CSTRING* cstring)
 
 	if (cstring->cstr_length > cstring->cstr_allocated && cstring->cstr_allocated)
 	{
-		free_cstring(xdrs, cstring);
+		cstring->free(xdrs);
 	}
 
 	if (!cstring->cstr_address)
@@ -1263,7 +1262,7 @@ static bool alloc_cstring(RemoteXdr* xdrs, CSTRING* cstring)
 }
 
 
-static void free_cstring( RemoteXdr* xdrs, CSTRING* cstring)
+void CSTRING::free(RemoteXdr* xdrs)
 {
 /**************************************
  *
@@ -1276,14 +1275,15 @@ static void free_cstring( RemoteXdr* xdrs, CSTRING* cstring)
  *
  **************************************/
 
-	if (cstring->cstr_allocated)
+	if (cstr_allocated)
 	{
-		delete[] cstring->cstr_address;
-		DEBUG_XDR_FREE(xdrs, cstring, cstring->cstr_address, cstring->cstr_allocated);
+		delete[] cstr_address;
+		if (xdrs)
+			DEBUG_XDR_FREE(xdrs, this, cstr_address, cstr_allocated);
 	}
 
-	cstring->cstr_address = NULL;
-	cstring->cstr_allocated = 0;
+	cstr_address = NULL;
+	cstr_allocated = 0;
 }
 
 
@@ -1388,7 +1388,7 @@ static bool_t xdr_cstring_with_limit( RemoteXdr* xdrs, CSTRING* cstring, ULONG l
 		return TRUE;
 
 	case XDR_FREE:
-		free_cstring(xdrs, cstring);
+		cstring->free(xdrs);
 		return TRUE;
 	}
 
@@ -1497,7 +1497,7 @@ static bool_t xdr_longs( RemoteXdr* xdrs, CSTRING* cstring)
 		break;
 
 	case XDR_FREE:
-		free_cstring(xdrs, cstring);
+		cstring->free(xdrs);
 		return TRUE;
 	}
 

src/remote/protocol.h

@@ -303,11 +303,15 @@ enum P_OP
 
 // Count String Structure
 
+class RemoteXdr;
+
 typedef struct cstring
 {
 	ULONG	cstr_length;
 	ULONG	cstr_allocated;
 	UCHAR*	cstr_address;
+
+	void	free(RemoteXdr* xdrs = nullptr);
 } CSTRING;
 
 // CVC: Only used in p_blob, p_sgmt & p_ddl, to validate constness.