From c8a124385e9c48cbe753d8e3e8187bfe0dd2c5c2 Mon Sep 17 00:00:00 2001
From: Dale Whinham <daleyo@gmail.com>
Date: Fri, 11 Dec 2020 19:15:30 +0000
Subject: [PATCH] minimig: Add ACTION_SAME_LOCK to shared filesystem

Adapt upstream fix from a314.

This fixes some odd behaviour in Workbench such as:

 - Icons that were "Left Out" would reappear in their parent windows
   when refreshed.
 - Deleted files would not disappear from the window unless it was
   refreshed.

Original message from a314 commit:

This call is used in at least 2.1 to terminate directory traversal
when deleting a directory using Workbench. This sometimes caused
unhandled exceptions in a314d and much worse unintended files being
deleted!
---
 support/minimig/miminig_fs_messages.h | 20 ++++++++++++++++++++
 support/minimig/minimig_share.cpp     | 24 ++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/support/minimig/miminig_fs_messages.h b/support/minimig/miminig_fs_messages.h
index d65f906..bdc1af2 100644
--- a/support/minimig/miminig_fs_messages.h
+++ b/support/minimig/miminig_fs_messages.h
@@ -28,6 +28,7 @@
 #define ACTION_DISK_TYPE      32
 #define ACTION_DISK_CHANGE    33
 #define ACTION_SET_DATE       34
+#define ACTION_SAME_LOCK      40
 #define ACTION_SCREEN_MODE    994
 #define ACTION_READ_RETURN    1001
 #define ACTION_WRITE_RETURN   1002
@@ -74,6 +75,10 @@
 #define SHARED_LOCK    -2
 #define EXCLUSIVE_LOCK -1
 
+#define LOCK_DIFFERENT   -1
+#define LOCK_SAME        0
+#define LOCK_SAME_VOLUME 1
+
 #define MODE_OLDFILE    1005
 #define MODE_NEWFILE    1006
 #define MODE_READWRITE  1004
@@ -356,6 +361,21 @@ struct SetCommentResponse
 	long error_code;
 };
 
+struct SameLockRequest
+{
+	long sz;
+	long type;
+	long key1;
+	long key2;
+};
+
+struct SameLockResponse
+{
+	long sz;
+	long success;
+	long error_code;
+};
+
 struct DiskInfoRequest
 {
 	long sz;
diff --git a/support/minimig/minimig_share.cpp b/support/minimig/minimig_share.cpp
index 954ab77..f065360 100644
--- a/support/minimig/minimig_share.cpp
+++ b/support/minimig/minimig_share.cpp
@@ -781,6 +781,30 @@ static int process_request(void *reqres_buffer)
 			ret = 0;
 		}
 		break;
+
+		case ACTION_SAME_LOCK:
+		{
+			dbg_print("> ACTION_SAME_LOCK\n");
+			SameLockRequest *req = (SameLockRequest*)reqres_buffer;
+
+			uint32_t key1 = SWAP_INT(req->key1);
+			uint32_t key2 = SWAP_INT(req->key2);
+			
+			if ((locks.find(key1) == locks.end()) || (locks.find(key2) == locks.end()))
+			{
+				ret = LOCK_DIFFERENT;
+				break;
+			}
+			
+			if (locks[key1].path == locks[key2].path)
+			{
+				ret = LOCK_SAME;
+				break;
+			}
+
+			ret = LOCK_SAME_VOLUME;
+		}
+		break;
 	}
 
 	int success = ret ? 0 : 1;