[DragAndDrop] panic when dropping non-file objects #3596
Description
Description
Summary
A panic occurs when dropping a non-file object into the webview - for example a string or browser tab.
Details
internal/frontend/desktop/windows/frontend.go
on the call:
_file, err := objs.GetValueAtIndex(i)a nil value is returned with no error. Presumably because no value is actually available.
However this nil value is then used subsequently:
file := (*edge.ICoreWebView2File)(unsafe.Pointer(_file))
defer file.Release()Upon Release() the program panics.
panic: runtime error: invalid memory address or nil pointer dereference
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0xb8309e]
goroutine 1 [running, locked to thread]:
github.com/wailsapp/go-webview2/pkg/edge.(*ICoreWebView2File).Release(0x0)
C:/Users/mic/go/pkg/mod/github.com/wailsapp/go-webview2@v1.0.10/pkg/edge/ICoreWebView2File.go:25 +0x1e
panic({0xec12e0?, 0x1979990?})
C:/Program Files/Go/src/runtime/panic.go:770 +0x136
github.com/wailsapp/go-webview2/pkg/edge.(*ICoreWebView2File).GetPath(0x0)
C:/Users/mic/go/pkg/mod/github.com/wailsapp/go-webview2@v1.0.10/pkg/edge/ICoreWebView2File.go:31 +0x103
github.com/wailsapp/wails/v2/internal/frontend/desktop/windows.(*Frontend).processMessageWithAdditionalObjects(0xc00003a200, {0xc00001eaf8, 0x11}, 0x1e6c00308000, 0x1e6c002d0a80)
C:/Users/mic/go/pkg/mod/github.com/wailsapp/wails/v2@v2.9.1/internal/frontend/desktop/windows/frontend.go:746 +0x60e
github.com/wailsapp/go-webview2/pkg/edge.(*Chromium).MessageReceived(0xc0000dc6c0, 0x1e6c00308000, 0x1e6c002d0a80)
C:/Users/mic/go/pkg/mod/github.com/wailsapp/go-webview2@v1.0.10/pkg/edge/chromium.go:342 +0x3ee
github.com/wailsapp/go-webview2/pkg/edge._ICoreWebView2WebMessageReceivedEventHandlerInvoke(0xc000009140, 0x1e6c00308000, 0x1e6c002d0a80)
C:/Users/mic/go/pkg/mod/github.com/wailsapp/go-webview2@v1.0.10/pkg/edge/ICoreWebView2WebMessageReceivedEventHandler.go:28 +0x38
syscall.SyscallN(0x7ffd344fe1e0, {0xc000712610?, 0x1, 0x1c763c61c28?})
C:/Program Files/Go/src/runtime/syscall_windows.go:544 +0x11d
[...]
To Reproduce
- Enable DragAndDrop
- Add a drop target on the frontend --wails-drop-target
- Register a callback
OnFileDrop((x,y,f) => { console.log(f) }, true)- Drop a Browser Tab onto the element
Expected behaviour
Dropped non-file object should be disregarded
Screenshots
No response
Attempted Fixes
A simple nil check has alleviated the issue:
_file, err := objs.GetValueAtIndex(i)
if err != nil {
f.logger.Error("cannot get value at %d : %s", i, err.Error())
return
}
if _file == nil {
f.logger.Warning("object at %d is not a file", i)
continue
}
file := (*edge.ICoreWebView2File)(unsafe.Pointer(_file))
defer file.Release()System Details
# Wails
Version | v2.9.1
# System
┌─────────────────────────────────────────────────────────────────────────────────────────────────┐
| OS | Windows 10 Enterprise |
| Version | 2009 (Build: 19045) |
| ID | 22H2 |
| Go Version | go1.22.1 |
| Platform | windows |
| Architecture | amd64 |
| CPU | AMD Ryzen 7 PRO 4750U with Radeon Graphics |
| GPU | AMD Radeon(TM) Graphics (Advanced Micro Devices, Inc.) - Driver: 31.0.21024.5005 |
| Memory | 16GB |
└─────────────────────────────────────────────────────────────────────────────────────────────────┘
# Dependencies
┌───────────────────────────────────────────────────────┐
| Dependency | Package Name | Status | Version |
| WebView2 | N/A | Installed | 126.0.2592.87 |
| Nodejs | N/A | Installed | 20.12.1 |
| npm | N/A | Installed | 10.5.0 |
| *upx | N/A | Installed | upx 4.0.1 |
| *nsis | N/A | Available | |
└─────────────── * - Optional Dependency ───────────────┘
# Diagnosis
Optional package(s) installation details:
- nsis : More info at https://wails.io/docs/guides/windows-installer/
SUCCESS Your system is ready for Wails development!Additional context
No response