From dba561a2899a3edafc3d67443c907878155a8c18 Mon Sep 17 00:00:00 2001
From: Daniel <brikbusters@gmail.com>
Date: Sat, 13 Jan 2024 22:58:41 -0500
Subject: [PATCH] Force libwpd backend to NOT run open or close session opcodes
 Kind of unfortunate, but Windows already has the session open, and freaks out
 with obscure errors if you try and open a new session. So, the libwpd backend
 will simply give a fake response for these opcodes.

---
 src/libwpd.c | 67 +++++++++++++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 27 deletions(-)

diff --git a/src/libwpd.c b/src/libwpd.c
index 3e8ff19..ea9697f 100644
--- a/src/libwpd.c
+++ b/src/libwpd.c
@@ -13,13 +13,17 @@
 
 int ptp_comm_init(struct PtpRuntime *r) {
 	ptp_reset(r);
-	wpd_init(WPD_VERBOSE, L"Camlib WPD");
-
-	r->comm_backend = malloc(sizeof(struct WpdStruct));
 
 	// We are not using low-level I/O operations, so this is never used
 	r->max_packet_size = 512;
 
+	// in libwpd, this will only coinitalize the new thread. Orig thread may be dead.
+	wpd_init(WPD_VERBOSE, L"Camlib WPD");
+
+	if (r->comm_backend != NULL) return 0;
+
+	r->comm_backend = malloc(sizeof(struct WpdStruct));
+
 	return 0;	
 }
 
@@ -76,6 +80,10 @@ int ptp_send_bulk_packets(struct PtpRuntime *r, int length) {
 	struct LibWPDPtpCommand cmd;
 	struct PtpBulkContainer *bulk = (struct PtpBulkContainer*)(r->data);
 
+	if (bulk->code == PTP_OC_OpenSession || bulk->code == PTP_OC_CloseSession) {
+		return length;
+	}
+
 	if (bulk->type == PTP_PACKET_TYPE_COMMAND) {
 		cmd.code = bulk->code;
 		cmd.param_length = ptp_get_param_length(r);
@@ -131,33 +139,38 @@ int ptp_receive_bulk_packets(struct PtpRuntime *r) {
 	struct WpdStruct *wpd = (struct WpdStruct *)(r->comm_backend);
 	if (wpd == NULL) return PTP_IO_ERR;
 
+	// WPD doesn't let you send session opcodes
 	struct PtpBulkContainer *bulk = (struct PtpBulkContainer*)(r->data);
-	if (bulk->type == PTP_PACKET_TYPE_COMMAND) {
-		struct LibWPDPtpCommand cmd;
-		int b = wpd_receive_do_data(wpd, &cmd, (uint8_t *)(r->data + 12), r->data_length - 12);
-		if (b < 0) {
-			return PTP_IO_ERR;
-		}
-		
-		if (b == 0) {
-			bulk->length = 12;
-			bulk->type = PTP_PACKET_TYPE_RESPONSE;
-			bulk->code = cmd.code;
-			bulk->transaction = r->transaction + 1;
-		} else {
-			bulk->length = 12 + b;
-			bulk->type = PTP_PACKET_TYPE_DATA;
-			bulk->code = cmd.code;
-			bulk->transaction = r->transaction + 1;
+	if (bulk->code == PTP_OC_OpenSession || bulk->code == PTP_OC_CloseSession) {
+		bulk->length = 12;
+		bulk->code = PTP_RC_OK;
+		bulk->type = PTP_PACKET_TYPE_RESPONSE;
+		memset(bulk->params, 5 * sizeof(uint32_t), 0);
+		return 12;
+	}
 
-			struct PtpBulkContainer *resp = (struct PtpBulkContainer*)(r->data + 12 + b);
-			resp->length = 12;
-			resp->type = PTP_PACKET_TYPE_RESPONSE;
-			resp->code = cmd.code;
-			resp->transaction = r->transaction + 1;
-		}
+	struct LibWPDPtpCommand cmd;
+	int b = wpd_receive_do_data(wpd, &cmd, (uint8_t *)(r->data + 12), r->data_length - 12);
+	if (b < 0) {
+		return PTP_IO_ERR;
+	}
+	
+	if (b == 0) {
+		bulk->length = 12;
+		bulk->type = PTP_PACKET_TYPE_RESPONSE;
+		bulk->code = cmd.code;
+		bulk->transaction = r->transaction + 1;
 	} else {
-		// I remember doing this for a reason, need to figure out why
+		bulk->length = 12 + b;
+		bulk->type = PTP_PACKET_TYPE_DATA;
+		bulk->code = cmd.code;
+		bulk->transaction = r->transaction + 1;
+
+		struct PtpBulkContainer *resp = (struct PtpBulkContainer*)(r->data + 12 + b);
+		resp->length = 12;
+		resp->type = PTP_PACKET_TYPE_RESPONSE;
+		resp->code = cmd.code;
+		resp->transaction = r->transaction + 1;
 	}
 
 	return 0;