Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly.

1 files changed, 605 insertions, 0 deletions

diff --git a/PC/pyshellext.cpp b/PC/pyshellext.cpp
new file mode 100644
index 0000000..04fe61e
--- /dev/null
+++ b/PC/pyshellext.cpp
@@ -0,0 +1,605 @@
+// Support back to Vista
+#define _WIN32_WINNT _WIN32_WINNT_VISTA
+#include <sdkddkver.h>
+
+// Use WRL to define a classic COM class
+#define __WRL_CLASSIC_COM__
+#include <wrl.h>
+
+#include <windows.h>
+#include <shlobj.h>
+#include <shlwapi.h>
+#include <olectl.h>
+#include <strsafe.h>
+
+#include "pyshellext_h.h"
+
+#define DDWM_UPDATEWINDOW (WM_USER+3)
+
+static HINSTANCE hModule;
+static CLIPFORMAT cfDropDescription;
+static CLIPFORMAT cfDragWindow;
+
+static const LPCWSTR CLASS_SUBKEY = L"Software\\Classes\\CLSID\\{BEA218D2-6950-497B-9434-61683EC065FE}";
+static const LPCWSTR DRAG_MESSAGE = L"Open with %1";
+
+using namespace Microsoft::WRL;
+
+HRESULT FilenameListCchLengthA(LPCSTR pszSource, size_t cchMax, size_t *pcchLength, size_t *pcchCount) {
+    HRESULT hr = S_OK;
+    size_t count = 0;
+    size_t length = 0;
+
+    while (pszSource && pszSource[0]) {
+        size_t oneLength;
+        hr = StringCchLengthA(pszSource, cchMax - length, &oneLength);
+        if (FAILED(hr)) {
+            return hr;
+        }
+        count += 1;
+        length += oneLength + (strchr(pszSource, ' ') ? 3 : 1);
+        pszSource = &pszSource[oneLength + 1];
+    }
+
+    *pcchCount = count;
+    *pcchLength = length;
+    return hr;
+}
+
+HRESULT FilenameListCchLengthW(LPCWSTR pszSource, size_t cchMax, size_t *pcchLength, size_t *pcchCount) {
+    HRESULT hr = S_OK;
+    size_t count = 0;
+    size_t length = 0;
+
+    while (pszSource && pszSource[0]) {
+        size_t oneLength;
+        hr = StringCchLengthW(pszSource, cchMax - length, &oneLength);
+        if (FAILED(hr)) {
+            return hr;
+        }
+        count += 1;
+        length += oneLength + (wcschr(pszSource, ' ') ? 3 : 1);
+        pszSource = &pszSource[oneLength + 1];
+    }
+
+    *pcchCount = count;
+    *pcchLength = length;
+    return hr;
+}
+
+HRESULT FilenameListCchCopyA(STRSAFE_LPSTR pszDest, size_t cchDest, LPCSTR pszSource, LPCSTR pszSeparator) {
+    HRESULT hr = S_OK;
+    size_t count = 0;
+    size_t length = 0;
+
+    while (pszSource[0]) {
+        STRSAFE_LPSTR newDest;
+
+        hr = StringCchCopyExA(pszDest, cchDest, pszSource, &newDest, &cchDest, 0);
+        if (FAILED(hr)) {
+            return hr;
+        }
+        pszSource += (newDest - pszDest) + 1;
+        pszDest = PathQuoteSpacesA(pszDest) ? newDest + 2 : newDest;
+
+        if (pszSource[0]) {
+            hr = StringCchCopyExA(pszDest, cchDest, pszSeparator, &newDest, &cchDest, 0);
+            if (FAILED(hr)) {
+                return hr;
+            }
+            pszDest = newDest;
+        }
+    }
+
+    return hr;
+}
+
+HRESULT FilenameListCchCopyW(STRSAFE_LPWSTR pszDest, size_t cchDest, LPCWSTR pszSource, LPCWSTR pszSeparator) {
+    HRESULT hr = S_OK;
+    size_t count = 0;
+    size_t length = 0;
+
+    while (pszSource[0]) {
+        STRSAFE_LPWSTR newDest;
+
+        hr = StringCchCopyExW(pszDest, cchDest, pszSource, &newDest, &cchDest, 0);
+        if (FAILED(hr)) {
+            return hr;
+        }
+        pszSource += (newDest - pszDest) + 1;
+        pszDest = PathQuoteSpacesW(pszDest) ? newDest + 2 : newDest;
+
+        if (pszSource[0]) {
+            hr = StringCchCopyExW(pszDest, cchDest, pszSeparator, &newDest, &cchDest, 0);
+            if (FAILED(hr)) {
+                return hr;
+            }
+            pszDest = newDest;
+        }
+    }
+
+    return hr;
+}
+
+
+class PyShellExt : public RuntimeClass<
+    RuntimeClassFlags<ClassicCom>,
+    IDropTarget,
+    IPersistFile
+>
+{
+    LPOLESTR target, target_dir;
+    DWORD target_mode;
+
+    IDataObject *data_obj;
+
+public:
+    PyShellExt() : target(NULL), target_dir(NULL), target_mode(0), data_obj(NULL) {
+        OutputDebugString(L"PyShellExt::PyShellExt");
+    }
+
+    ~PyShellExt() {
+        if (target) {
+            CoTaskMemFree(target);
+        }
+        if (target_dir) {
+            CoTaskMemFree(target_dir);
+        }
+        if (data_obj) {
+            data_obj->Release();
+        }
+    }
+
+private:
+    HRESULT UpdateDropDescription(IDataObject *pDataObj) {
+        STGMEDIUM medium;
+        FORMATETC fmt = {
+            cfDropDescription,
+            NULL,
+            DVASPECT_CONTENT,
+            -1,
+            TYMED_HGLOBAL
+        };
+
+        auto hr = pDataObj->GetData(&fmt, &medium);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::UpdateDropDescription - failed to get DROPDESCRIPTION format");
+            return hr;
+        }
+        if (!medium.hGlobal) {
+            OutputDebugString(L"PyShellExt::UpdateDropDescription - DROPDESCRIPTION format had NULL hGlobal");
+            ReleaseStgMedium(&medium);
+            return E_FAIL;
+        }
+        auto dd = (DROPDESCRIPTION*)GlobalLock(medium.hGlobal);
+        StringCchCopy(dd->szMessage, sizeof(dd->szMessage) / sizeof(dd->szMessage[0]), DRAG_MESSAGE);
+        StringCchCopy(dd->szInsert, sizeof(dd->szInsert) / sizeof(dd->szInsert[0]), PathFindFileNameW(target));
+        dd->type = DROPIMAGE_MOVE;
+
+        GlobalUnlock(medium.hGlobal);
+        ReleaseStgMedium(&medium);
+
+        return S_OK;
+    }
+
+    HRESULT GetDragWindow(IDataObject *pDataObj, HWND *phWnd) {
+        HRESULT hr;
+        HWND *pMem;
+        STGMEDIUM medium;
+        FORMATETC fmt = {
+            cfDragWindow,
+            NULL,
+            DVASPECT_CONTENT,
+            -1,
+            TYMED_HGLOBAL
+        };
+
+        hr = pDataObj->GetData(&fmt, &medium);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::GetDragWindow - failed to get DragWindow format");
+            return hr;
+        }
+        if (!medium.hGlobal) {
+            OutputDebugString(L"PyShellExt::GetDragWindow - DragWindow format had NULL hGlobal");
+            ReleaseStgMedium(&medium);
+            return E_FAIL;
+        }
+
+        pMem = (HWND*)GlobalLock(medium.hGlobal);
+        if (!pMem) {
+            OutputDebugString(L"PyShellExt::GetDragWindow - failed to lock DragWindow hGlobal");
+            ReleaseStgMedium(&medium);
+            return E_FAIL;
+        }
+
+        *phWnd = *pMem;
+
+        GlobalUnlock(medium.hGlobal);
+        ReleaseStgMedium(&medium);
+
+        return S_OK;
+    }
+
+    HRESULT GetArguments(IDataObject *pDataObj, LPCWSTR *pArguments) {
+        HRESULT hr;
+        DROPFILES *pdropfiles;
+
+        STGMEDIUM medium;
+        FORMATETC fmt = {
+            CF_HDROP,
+            NULL,
+            DVASPECT_CONTENT,
+            -1,
+            TYMED_HGLOBAL
+        };
+
+        hr = pDataObj->GetData(&fmt, &medium);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::GetArguments - failed to get CF_HDROP format");
+            return hr;
+        }
+        if (!medium.hGlobal) {
+            OutputDebugString(L"PyShellExt::GetArguments - CF_HDROP format had NULL hGlobal");
+            ReleaseStgMedium(&medium);
+            return E_FAIL;
+        }
+
+        pdropfiles = (DROPFILES*)GlobalLock(medium.hGlobal);
+        if (!pdropfiles) {
+            OutputDebugString(L"PyShellExt::GetArguments - failed to lock CF_HDROP hGlobal");
+            ReleaseStgMedium(&medium);
+            return E_FAIL;
+        }
+
+        if (pdropfiles->fWide) {
+            LPCWSTR files = (LPCWSTR)((char*)pdropfiles + pdropfiles->pFiles);
+            size_t len, count;
+            hr = FilenameListCchLengthW(files, 32767, &len, &count);
+            if (SUCCEEDED(hr)) {
+                LPWSTR args = (LPWSTR)CoTaskMemAlloc(sizeof(WCHAR) * (len + 1));
+                if (args) {
+                    hr = FilenameListCchCopyW(args, 32767, files, L" ");
+                    if (SUCCEEDED(hr)) {
+                        *pArguments = args;
+                    } else {
+                        CoTaskMemFree(args);
+                    }
+                } else {
+                    hr = E_OUTOFMEMORY;
+                }
+            }
+        } else {
+            LPCSTR files = (LPCSTR)((char*)pdropfiles + pdropfiles->pFiles);
+            size_t len, count;
+            hr = FilenameListCchLengthA(files, 32767, &len, &count);
+            if (SUCCEEDED(hr)) {
+                LPSTR temp = (LPSTR)CoTaskMemAlloc(sizeof(CHAR) * (len + 1));
+                if (temp) {
+                    hr = FilenameListCchCopyA(temp, 32767, files, " ");
+                    if (SUCCEEDED(hr)) {
+                        int wlen = MultiByteToWideChar(CP_ACP, 0, temp, (int)len, NULL, 0);
+                        if (wlen) {
+                            LPWSTR args = (LPWSTR)CoTaskMemAlloc(sizeof(WCHAR) * (wlen + 1));
+                            if (MultiByteToWideChar(CP_ACP, 0, temp, (int)len, args, wlen + 1)) {
+                                *pArguments = args;
+                            } else {
+                                OutputDebugString(L"PyShellExt::GetArguments - failed to convert multi-byte to wide-char path");
+                                CoTaskMemFree(args);
+                                hr = E_FAIL;
+                            }
+                        } else {
+                            OutputDebugString(L"PyShellExt::GetArguments - failed to get length of wide-char path");
+                            hr = E_FAIL;
+                        }
+                    }
+                    CoTaskMemFree(temp);
+                } else {
+                    hr = E_OUTOFMEMORY;
+                }
+            }
+        }
+
+        GlobalUnlock(medium.hGlobal);
+        ReleaseStgMedium(&medium);
+
+        return hr;
+    }
+
+    HRESULT NotifyDragWindow(HWND hwnd) {
+        LRESULT res;
+
+        if (!hwnd) {
+            return S_FALSE;
+        }
+
+        res = SendMessage(hwnd, DDWM_UPDATEWINDOW, 0, NULL);
+
+        if (res) {
+            OutputDebugString(L"PyShellExt::NotifyDragWindow - failed to post DDWM_UPDATEWINDOW");
+            return E_FAIL;
+        }
+
+        return S_OK;
+    }
+
+public:
+    // IDropTarget implementation
+
+    STDMETHODIMP DragEnter(IDataObject *pDataObj, DWORD grfKeyState, POINTL pt, DWORD *pdwEffect) {
+        HWND hwnd;
+
+        OutputDebugString(L"PyShellExt::DragEnter");
+
+        pDataObj->AddRef();
+        data_obj = pDataObj;
+
+        *pdwEffect = DROPEFFECT_MOVE;
+
+        if (FAILED(UpdateDropDescription(data_obj))) {
+            OutputDebugString(L"PyShellExt::DragEnter - failed to update drop description");
+        }
+        if (FAILED(GetDragWindow(data_obj, &hwnd))) {
+            OutputDebugString(L"PyShellExt::DragEnter - failed to get drag window");
+        }
+        if (FAILED(NotifyDragWindow(hwnd))) {
+            OutputDebugString(L"PyShellExt::DragEnter - failed to notify drag window");
+        }
+
+        return S_OK;
+    }
+
+    STDMETHODIMP DragLeave() {
+        return S_OK;
+    }
+
+    STDMETHODIMP DragOver(DWORD grfKeyState, POINTL pt, DWORD *pdwEffect) {
+        return S_OK;
+    }
+
+    STDMETHODIMP Drop(IDataObject *pDataObj, DWORD grfKeyState, POINTL pt, DWORD *pdwEffect) {
+        LPCWSTR args;
+
+        OutputDebugString(L"PyShellExt::Drop");
+        *pdwEffect = DROPEFFECT_NONE;
+
+        if (pDataObj != data_obj) {
+            OutputDebugString(L"PyShellExt::Drop - unexpected data object");
+            return E_FAIL;
+        }
+
+        data_obj->Release();
+        data_obj = NULL;
+
+        if (SUCCEEDED(GetArguments(pDataObj, &args))) {
+            OutputDebugString(args);
+            ShellExecute(NULL, NULL, target, args, target_dir, SW_NORMAL);
+
+            CoTaskMemFree((LPVOID)args);
+        } else {
+            OutputDebugString(L"PyShellExt::Drop - failed to get launch arguments");
+        }
+
+        return S_OK;
+    }
+
+    // IPersistFile implementation
+
+    STDMETHODIMP GetCurFile(LPOLESTR *ppszFileName) {
+        HRESULT hr;
+        size_t len;
+
+        if (!ppszFileName) {
+            return E_POINTER;
+        }
+
+        hr = StringCchLength(target, STRSAFE_MAX_CCH - 1, &len);
+        if (FAILED(hr)) {
+            return E_FAIL;
+        }
+
+        *ppszFileName = (LPOLESTR)CoTaskMemAlloc(sizeof(WCHAR) * (len + 1));
+        if (!*ppszFileName) {
+            return E_OUTOFMEMORY;
+        }
+
+        hr = StringCchCopy(*ppszFileName, len + 1, target);
+        if (FAILED(hr)) {
+            CoTaskMemFree(*ppszFileName);
+            *ppszFileName = NULL;
+            return E_FAIL;
+        }
+
+        return S_OK;
+    }
+
+    STDMETHODIMP IsDirty() {
+        return S_FALSE;
+    }
+
+    STDMETHODIMP Load(LPCOLESTR pszFileName, DWORD dwMode) {
+        HRESULT hr;
+        size_t len;
+
+        OutputDebugString(L"PyShellExt::Load");
+        OutputDebugString(pszFileName);
+
+        hr = StringCchLength(pszFileName, STRSAFE_MAX_CCH - 1, &len);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::Load - failed to get string length");
+            return hr;
+        }
+
+        if (target) {
+            CoTaskMemFree(target);
+        }
+        if (target_dir) {
+            CoTaskMemFree(target_dir);
+        }
+
+        target = (LPOLESTR)CoTaskMemAlloc(sizeof(WCHAR) * (len + 1));
+        if (!target) {
+            OutputDebugString(L"PyShellExt::Load - E_OUTOFMEMORY");
+            return E_OUTOFMEMORY;
+        }
+        target_dir = (LPOLESTR)CoTaskMemAlloc(sizeof(WCHAR) * (len + 1));
+        if (!target_dir) {
+            OutputDebugString(L"PyShellExt::Load - E_OUTOFMEMORY");
+            return E_OUTOFMEMORY;
+        }
+
+        hr = StringCchCopy(target, len + 1, pszFileName);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::Load - failed to copy string");
+            return hr;
+        }
+
+        hr = StringCchCopy(target_dir, len + 1, pszFileName);
+        if (FAILED(hr)) {
+            OutputDebugString(L"PyShellExt::Load - failed to copy string");
+            return hr;
+        }
+        if (!PathRemoveFileSpecW(target_dir)) {
+            OutputDebugStringW(L"PyShellExt::Load - failed to remove filespec from target");
+            return E_FAIL;
+        }
+
+        OutputDebugString(target);
+        target_mode = dwMode;
+        OutputDebugString(L"PyShellExt::Load - S_OK");
+        return S_OK;
+    }
+
+    STDMETHODIMP Save(LPCOLESTR pszFileName, BOOL fRemember) {
+        return E_NOTIMPL;
+    }
+
+    STDMETHODIMP SaveCompleted(LPCOLESTR pszFileName) {
+        return E_NOTIMPL;
+    }
+
+    STDMETHODIMP GetClassID(CLSID *pClassID) {
+        *pClassID = CLSID_PyShellExt;
+        return S_OK;
+    }
+};
+
+CoCreatableClass(PyShellExt);
+
+STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, _COM_Outptr_ void** ppv) {
+    return Module<InProc>::GetModule().GetClassObject(rclsid, riid, ppv);
+}
+
+STDAPI DllCanUnloadNow() {
+    return Module<InProc>::GetModule().Terminate() ? S_OK : S_FALSE;
+}
+
+STDAPI DllRegisterServer() {
+    LONG res;
+    SECURITY_ATTRIBUTES secattr = { sizeof(SECURITY_ATTRIBUTES), NULL, FALSE };
+    LPSECURITY_ATTRIBUTES psecattr = NULL;
+    HKEY key, ipsKey;
+    WCHAR modname[MAX_PATH];
+    DWORD modname_len;
+
+    OutputDebugString(L"PyShellExt::DllRegisterServer");
+    if (!hModule) {
+        OutputDebugString(L"PyShellExt::DllRegisterServer - module handle was not set");
+        return SELFREG_E_CLASS;
+    }
+    modname_len = GetModuleFileName(hModule, modname, MAX_PATH);
+    if (modname_len == 0 ||
+        (modname_len == MAX_PATH && GetLastError() == ERROR_INSUFFICIENT_BUFFER)) {
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to get module file name");
+        return SELFREG_E_CLASS;
+    }
+
+    DWORD disp;
+    res = RegCreateKeyEx(HKEY_LOCAL_MACHINE, CLASS_SUBKEY, 0, NULL, 0,
+        KEY_ALL_ACCESS, psecattr, &key, &disp);
+    if (res == ERROR_ACCESS_DENIED) {
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to write per-machine registration. Attempting per-user instead.");
+        res = RegCreateKeyEx(HKEY_CURRENT_USER, CLASS_SUBKEY, 0, NULL, 0,
+            KEY_ALL_ACCESS, psecattr, &key, &disp);
+    }
+    if (res != ERROR_SUCCESS) {
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to create class key");
+        return SELFREG_E_CLASS;
+    }
+
+    res = RegCreateKeyEx(key, L"InProcServer32", 0, NULL, 0,
+        KEY_ALL_ACCESS, psecattr, &ipsKey, NULL);
+    if (res != ERROR_SUCCESS) {
+        RegCloseKey(key);
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to create InProcServer32 key");
+        return SELFREG_E_CLASS;
+    }
+
+    res = RegSetValueEx(ipsKey, NULL, 0,
+        REG_SZ, (LPBYTE)modname, modname_len * sizeof(modname[0]));
+
+    if (res != ERROR_SUCCESS) {
+        RegCloseKey(ipsKey);
+        RegCloseKey(key);
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to set server path");
+        return SELFREG_E_CLASS;
+    }
+
+    res = RegSetValueEx(ipsKey, L"ThreadingModel", 0,
+        REG_SZ, (LPBYTE)(L"Apartment"), sizeof(L"Apartment"));
+
+    RegCloseKey(ipsKey);
+    RegCloseKey(key);
+    if (res != ERROR_SUCCESS) {
+        OutputDebugString(L"PyShellExt::DllRegisterServer - failed to set threading model");
+        return SELFREG_E_CLASS;
+    }
+
+    SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, NULL, NULL);
+
+    OutputDebugString(L"PyShellExt::DllRegisterServer - S_OK");
+    return S_OK;
+}
+
+STDAPI DllUnregisterServer() {
+    LONG res_lm, res_cu;
+
+    res_lm = RegDeleteTree(HKEY_LOCAL_MACHINE, CLASS_SUBKEY);
+    if (res_lm != ERROR_SUCCESS && res_lm != ERROR_FILE_NOT_FOUND) {
+        OutputDebugString(L"PyShellExt::DllUnregisterServer - failed to delete per-machine registration");
+        return SELFREG_E_CLASS;
+    }
+
+    res_cu = RegDeleteTree(HKEY_CURRENT_USER, CLASS_SUBKEY);
+    if (res_cu != ERROR_SUCCESS && res_cu != ERROR_FILE_NOT_FOUND) {
+        OutputDebugString(L"PyShellExt::DllUnregisterServer - failed to delete per-user registration");
+        return SELFREG_E_CLASS;
+    }
+
+    if (res_lm == ERROR_FILE_NOT_FOUND && res_cu == ERROR_FILE_NOT_FOUND) {
+        OutputDebugString(L"PyShellExt::DllUnregisterServer - extension was not registered");
+        return SELFREG_E_CLASS;
+    }
+
+    SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, NULL, NULL);
+
+    OutputDebugString(L"PyShellExt::DllUnregisterServer - S_OK");
+    return S_OK;
+}
+
+STDAPI_(BOOL) DllMain(_In_opt_ HINSTANCE hinst, DWORD reason, _In_opt_ void*) {
+    if (reason == DLL_PROCESS_ATTACH) {
+        hModule = hinst;
+
+        cfDropDescription = RegisterClipboardFormat(CFSTR_DROPDESCRIPTION);
+        if (!cfDropDescription) {
+            OutputDebugString(L"PyShellExt::DllMain - failed to get CFSTR_DROPDESCRIPTION format");
+        }
+        cfDragWindow = RegisterClipboardFormat(L"DragWindow");
+        if (!cfDragWindow) {
+            OutputDebugString(L"PyShellExt::DllMain - failed to get DragWindow format");
+        }
+
+        DisableThreadLibraryCalls(hinst);
+    }
+    return TRUE;
+}
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