From dcab3151f050778ff21c5e63dc02e2753238e7df Mon Sep 17 00:00:00 2001
From: alvinhochun <alvin@alvinhc.com>
Date: Mon, 6 Dec 2021 00:51:39 +0800
Subject: [PATCH] Fix SetCursorPos and ClipCursor ignoring DPI awareness

---
 Sandboxie/core/dll/guimisc.c     | 15 +++++++++++++++
 Sandboxie/core/svc/GuiServer.cpp | 27 +++++++++++++++++++++++++++
 Sandboxie/core/svc/GuiWire.h     |  2 ++
 3 files changed, 44 insertions(+)

diff --git a/Sandboxie/core/dll/guimisc.c b/Sandboxie/core/dll/guimisc.c
index 7622d90d..38cad43e 100644
--- a/Sandboxie/core/dll/guimisc.c
+++ b/Sandboxie/core/dll/guimisc.c
@@ -123,6 +123,16 @@ typedef int (*P_ReleaseDC)(
 
 static P_GetUserObjectInformationW __sys_GetUserObjectInformationW = NULL;
 
+#ifndef _DPI_AWARENESS_CONTEXTS_
+struct DPI_AWARENESS_CONTEXT__ { int unused; };
+typedef DPI_AWARENESS_CONTEXT__ *DPI_AWARENESS_CONTEXT;
+#endif
+
+typedef DPI_AWARENESS_CONTEXT (WINAPI *P_GetThreadDpiAwarenessContext)(
+    VOID);
+
+static P_GetThreadDpiAwarenessContext __sys_GetThreadDpiAwarenessContext = NULL;
+
 
 //---------------------------------------------------------------------------
 // Variables
@@ -230,6 +240,9 @@ _FX BOOLEAN Gui_InitMisc(void)
     SBIEDLL_HOOK_GUI(GetRawInputDeviceInfoA);
     SBIEDLL_HOOK_GUI(GetRawInputDeviceInfoW);
 
+	__sys_GetThreadDpiAwarenessContext = (P_GetThreadDpiAwarenessContext)
+		Ldr_GetProcAddrNew(DllName_user32, L"GetThreadDpiAwarenessContext","GetThreadDpiAwarenessContext");
+
     return TRUE;
 }
 
@@ -314,6 +327,7 @@ _FX BOOL Gui_ClipCursor(const RECT *lpRect)
         memzero(&req.rect, sizeof(req.rect));
         Gui_ClipCursorActive = FALSE;
     }
+    req.dpi_awareness_ctx = __sys_GetThreadDpiAwarenessContext ? (LONG64)(LONG_PTR)__sys_GetThreadDpiAwarenessContext() : 0;
 
     rpl = Gui_CallProxy(&req, sizeof(req), sizeof(ULONG));
     if (rpl) {
@@ -465,6 +479,7 @@ _FX BOOL Gui_SetCursorPos(int x, int y)
     req.error = GetLastError();
     req.x = x;
     req.y = y;
+    req.dpi_awareness_ctx = __sys_GetThreadDpiAwarenessContext ? (LONG64)(LONG_PTR)__sys_GetThreadDpiAwarenessContext() : 0;
     rpl = Gui_CallProxyEx(&req, sizeof(req), sizeof(ULONG), TRUE);
     if (rpl) {
         retval = rpl->retval;
diff --git a/Sandboxie/core/svc/GuiServer.cpp b/Sandboxie/core/svc/GuiServer.cpp
index 7007da58..bda5c33c 100644
--- a/Sandboxie/core/svc/GuiServer.cpp
+++ b/Sandboxie/core/svc/GuiServer.cpp
@@ -85,6 +85,14 @@ typedef struct _WND_HOOK {
 
 static HWND DDE_Request_ProxyWnd = NULL;
 
+#ifndef _DPI_AWARENESS_CONTEXTS_
+struct DPI_AWARENESS_CONTEXT__ { int unused; };
+typedef DPI_AWARENESS_CONTEXT__ *DPI_AWARENESS_CONTEXT;
+#endif
+typedef DPI_AWARENESS_CONTEXT (WINAPI *P_SetThreadDpiAwarenessContext)(
+    DPI_AWARENESS_CONTEXT dpiContext);
+
+static P_SetThreadDpiAwarenessContext __sys_SetThreadDpiAwarenessContext = NULL;
 
 //---------------------------------------------------------------------------
 // Constructor
@@ -113,6 +121,9 @@ GuiServer::GuiServer()
 	else*/
 	GetVersionExW(&osvi); // since windows 10 this one is lying
     m_nOSVersion = osvi.dwMajorVersion * 10 + osvi.dwMinorVersion;
+
+    __sys_SetThreadDpiAwarenessContext = (P_SetThreadDpiAwarenessContext)GetProcAddress(
+        GetModuleHandle(L"user32.dll"), "SetThreadDpiAwarenessContext");
 }
 
 
@@ -3043,9 +3054,17 @@ ULONG GuiServer::ClipCursorSlave(SlaveArgs *args)
     if (req->have_rect)
         rect = &req->rect;
 
+    DPI_AWARENESS_CONTEXT old_trd_dpi_ctx = __sys_SetThreadDpiAwarenessContext
+        ? __sys_SetThreadDpiAwarenessContext((DPI_AWARENESS_CONTEXT)(LONG_PTR)req->dpi_awareness_ctx)
+        : NULL;
+
     ClipCursor(rect); //if (! ) // as this seems to randomly fail, don't issue errors
     //    return STATUS_ACCESS_DENIED; // todo: add reply and return ret value
 
+    if (__sys_SetThreadDpiAwarenessContext) {
+        __sys_SetThreadDpiAwarenessContext(old_trd_dpi_ctx);
+    }
+
     return STATUS_SUCCESS;
 }
 
@@ -3339,11 +3358,19 @@ ULONG GuiServer::SetCursorPosSlave(SlaveArgs *args)
     if (args->req_len != sizeof(GUI_SET_CURSOR_POS_REQ))
         return STATUS_INFO_LENGTH_MISMATCH;
 
+    DPI_AWARENESS_CONTEXT old_trd_dpi_ctx = __sys_SetThreadDpiAwarenessContext
+        ? __sys_SetThreadDpiAwarenessContext((DPI_AWARENESS_CONTEXT)(LONG_PTR)req->dpi_awareness_ctx)
+        : NULL;
+
     SetLastError(req->error);
 
     rpl->retval = (ULONG)SetCursorPos(req->x, req->y);
     rpl->error = GetLastError();
 
+    if (__sys_SetThreadDpiAwarenessContext) {
+        __sys_SetThreadDpiAwarenessContext(old_trd_dpi_ctx);
+    }
+
     args->rpl_len = sizeof(GUI_SET_CURSOR_POS_RPL);
     return STATUS_SUCCESS;
 }
diff --git a/Sandboxie/core/svc/GuiWire.h b/Sandboxie/core/svc/GuiWire.h
index 36e6bfa0..3eb5d47d 100644
--- a/Sandboxie/core/svc/GuiWire.h
+++ b/Sandboxie/core/svc/GuiWire.h
@@ -545,6 +545,7 @@ struct tagGUI_CLIP_CURSOR_REQ
     ULONG msgid;
     BOOLEAN have_rect;
     RECT rect;
+    LONG64 dpi_awareness_ctx;
 };
 
 typedef struct tagGUI_CLIP_CURSOR_REQ GUI_CLIP_CURSOR_REQ;
@@ -646,6 +647,7 @@ struct tagGUI_SET_CURSOR_POS_REQ
     ULONG error;
     LONG x;
     LONG y;
+    LONG64 dpi_awareness_ctx;
 };
 
 struct tagGUI_SET_CURSOR_POS_RPL