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Diffstat (limited to '')
| -rw-r--r-- | uriloader/exthandler/win/nsOSHelperAppService.cpp | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/uriloader/exthandler/win/nsOSHelperAppService.cpp b/uriloader/exthandler/win/nsOSHelperAppService.cpp new file mode 100644 index 0000000000..8d23dd758d --- /dev/null +++ b/uriloader/exthandler/win/nsOSHelperAppService.cpp @@ -0,0 +1,612 @@ +/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim:set ts=2 sts=2 sw=2 et cin: + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsComponentManagerUtils.h" +#include "nsOSHelperAppService.h" +#include "nsISupports.h" +#include "nsString.h" +#include "nsIMIMEInfo.h" +#include "nsMIMEInfoWin.h" +#include "nsMimeTypes.h" +#include "nsNativeCharsetUtils.h" +#include "nsLocalFile.h" +#include "nsIWindowsRegKey.h" +#include "nsXULAppAPI.h" +#include "mozilla/UniquePtrExtensions.h" +#include "mozilla/WindowsVersion.h" + +// shellapi.h is needed to build with WIN32_LEAN_AND_MEAN +#include <shellapi.h> +#include <shlwapi.h> + +#define LOG(...) MOZ_LOG(sLog, mozilla::LogLevel::Debug, (__VA_ARGS__)) + +// helper methods: forward declarations... +static nsresult GetExtensionFromWindowsMimeDatabase(const nsACString& aMimeType, + nsString& aFileExtension); + +nsOSHelperAppService::nsOSHelperAppService() + : nsExternalHelperAppService(), mAppAssoc(nullptr) { + CoInitialize(nullptr); + CoCreateInstance(CLSID_ApplicationAssociationRegistration, nullptr, + CLSCTX_INPROC, IID_IApplicationAssociationRegistration, + (void**)&mAppAssoc); +} + +nsOSHelperAppService::~nsOSHelperAppService() { + if (mAppAssoc) mAppAssoc->Release(); + mAppAssoc = nullptr; + CoUninitialize(); +} + +// The windows registry provides a mime database key which lists a set of mime +// types and corresponding "Extension" values. we can use this to look up our +// mime type to see if there is a preferred extension for the mime type. +static nsresult GetExtensionFromWindowsMimeDatabase(const nsACString& aMimeType, + nsString& aFileExtension) { + nsAutoString mimeDatabaseKey; + mimeDatabaseKey.AssignLiteral("MIME\\Database\\Content Type\\"); + + AppendASCIItoUTF16(aMimeType, mimeDatabaseKey); + + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return NS_ERROR_NOT_AVAILABLE; + + nsresult rv = + regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, mimeDatabaseKey, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + + if (NS_SUCCEEDED(rv)) + regKey->ReadStringValue(u"Extension"_ns, aFileExtension); + + return NS_OK; +} + +nsresult nsOSHelperAppService::OSProtocolHandlerExists( + const char* aProtocolScheme, bool* aHandlerExists) { + // look up the protocol scheme in the windows registry....if we find a match + // then we have a handler for it... + *aHandlerExists = false; + if (aProtocolScheme && *aProtocolScheme) { + NS_ENSURE_TRUE(mAppAssoc, NS_ERROR_NOT_AVAILABLE); + wchar_t* pResult = nullptr; + NS_ConvertASCIItoUTF16 scheme(aProtocolScheme); + // We are responsible for freeing returned strings. + HRESULT hr = mAppAssoc->QueryCurrentDefault(scheme.get(), AT_URLPROTOCOL, + AL_EFFECTIVE, &pResult); + if (SUCCEEDED(hr)) { + CoTaskMemFree(pResult); + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) { + return NS_ERROR_NOT_AVAILABLE; + } + + nsresult rv = regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, + nsDependentString(scheme.get()), + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) { + // Open will fail if the registry key path doesn't exist. + return NS_OK; + } + + bool hasValue; + rv = regKey->HasValue(u"URL Protocol"_ns, &hasValue); + if (NS_FAILED(rv)) { + return NS_ERROR_FAILURE; + } + if (!hasValue) { + return NS_OK; + } + + *aHandlerExists = true; + } + } + + return NS_OK; +} + +NS_IMETHODIMP nsOSHelperAppService::GetApplicationDescription( + const nsACString& aScheme, nsAString& _retval) { + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return NS_ERROR_NOT_AVAILABLE; + + NS_ConvertASCIItoUTF16 buf(aScheme); + + if (mozilla::IsWin8OrLater()) { + wchar_t result[1024]; + DWORD resultSize = 1024; + HRESULT hr = AssocQueryString(0x1000 /* ASSOCF_IS_PROTOCOL */, + ASSOCSTR_FRIENDLYAPPNAME, buf.get(), NULL, + result, &resultSize); + if (SUCCEEDED(hr)) { + _retval = result; + return NS_OK; + } + } + + NS_ENSURE_TRUE(mAppAssoc, NS_ERROR_NOT_AVAILABLE); + wchar_t* pResult = nullptr; + // We are responsible for freeing returned strings. + HRESULT hr = mAppAssoc->QueryCurrentDefault(buf.get(), AT_URLPROTOCOL, + AL_EFFECTIVE, &pResult); + if (SUCCEEDED(hr)) { + nsCOMPtr<nsIFile> app; + nsAutoString appInfo(pResult); + CoTaskMemFree(pResult); + if (NS_SUCCEEDED(GetDefaultAppInfo(appInfo, _retval, getter_AddRefs(app)))) + return NS_OK; + } + return NS_ERROR_NOT_AVAILABLE; +} + +NS_IMETHODIMP nsOSHelperAppService::IsCurrentAppOSDefaultForProtocol( + const nsACString& aScheme, bool* _retval) { + *_retval = false; + + NS_ENSURE_TRUE(mAppAssoc, NS_ERROR_NOT_AVAILABLE); + + NS_ConvertASCIItoUTF16 buf(aScheme); + + // Find the progID + wchar_t* pResult = nullptr; + HRESULT hr = mAppAssoc->QueryCurrentDefault(buf.get(), AT_URLPROTOCOL, + AL_EFFECTIVE, &pResult); + if (FAILED(hr)) { + return NS_ERROR_FAILURE; + } + nsAutoString progID(pResult); + // We are responsible for freeing returned strings. + CoTaskMemFree(pResult); + + // Find the default executable. + nsAutoString description; + nsCOMPtr<nsIFile> appFile; + nsresult rv = GetDefaultAppInfo(progID, description, getter_AddRefs(appFile)); + if (NS_FAILED(rv)) { + return rv; + } + // Determine if the default executable is our executable. + nsCOMPtr<nsIFile> ourBinary; + XRE_GetBinaryPath(getter_AddRefs(ourBinary)); + bool isSame = false; + rv = appFile->Equals(ourBinary, &isSame); + if (NS_FAILED(rv)) { + return rv; + } + *_retval = isSame; + return NS_OK; +} + +// GetMIMEInfoFromRegistry: This function obtains the values of some of the +// nsIMIMEInfo attributes for the mimeType/extension associated with the input +// registry key. The default entry for that key is the name of a registry key +// under HKEY_CLASSES_ROOT. The default value for *that* key is the descriptive +// name of the type. The EditFlags value is a binary value; the low order bit +// of the third byte of which indicates that the user does not need to be +// prompted. +// +// This function sets only the Description attribute of the input nsIMIMEInfo. +/* static */ +nsresult nsOSHelperAppService::GetMIMEInfoFromRegistry(const nsString& fileType, + nsIMIMEInfo* pInfo) { + nsresult rv = NS_OK; + + NS_ENSURE_ARG(pInfo); + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return NS_ERROR_NOT_AVAILABLE; + + rv = regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, fileType, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) return NS_ERROR_FAILURE; + + // OK, the default value here is the description of the type. + nsAutoString description; + rv = regKey->ReadStringValue(u""_ns, description); + if (NS_SUCCEEDED(rv)) pInfo->SetDescription(description); + + return NS_OK; +} + +///////////////////////////////////////////////////////////////////////////////////////////////// +// method overrides used to gather information from the windows registry for +// various mime types. +//////////////////////////////////////////////////////////////////////////////////////////////// + +/// Looks up the type for the extension aExt and compares it to aType +/* static */ +bool nsOSHelperAppService::typeFromExtEquals(const char16_t* aExt, + const char* aType) { + if (!aType) return false; + nsAutoString fileExtToUse; + if (aExt[0] != char16_t('.')) fileExtToUse = char16_t('.'); + + fileExtToUse.Append(aExt); + + bool eq = false; + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return eq; + + nsresult rv = + regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, fileExtToUse, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) return eq; + + nsAutoString type; + rv = regKey->ReadStringValue(u"Content Type"_ns, type); + if (NS_SUCCEEDED(rv)) eq = type.LowerCaseEqualsASCII(aType); + + return eq; +} + +// The "real" name of a given helper app (as specified by the path to the +// executable file held in various registry keys) is stored n the VERSIONINFO +// block in the file's resources. We need to find the path to the executable +// and then retrieve the "FileDescription" field value from the file. +nsresult nsOSHelperAppService::GetDefaultAppInfo( + const nsAString& aAppInfo, nsAString& aDefaultDescription, + nsIFile** aDefaultApplication) { + nsAutoString handlerCommand; + + // If all else fails, use the file type key name, which will be + // something like "pngfile" for .pngs, "WMVFile" for .wmvs, etc. + aDefaultDescription = aAppInfo; + *aDefaultApplication = nullptr; + + if (aAppInfo.IsEmpty()) return NS_ERROR_FAILURE; + + // aAppInfo may be a file, file path, program id, or + // Applications reference - + // c:\dir\app.exe + // Applications\appfile.exe/dll (shell\open...) + // ProgID.progid (shell\open...) + + nsAutoString handlerKeyName(aAppInfo); + + nsCOMPtr<nsIWindowsRegKey> chkKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!chkKey) return NS_ERROR_FAILURE; + + nsresult rv = + chkKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, handlerKeyName, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) { + // It's a file system path to a handler + handlerCommand.Assign(aAppInfo); + } else { + handlerKeyName.AppendLiteral("\\shell\\open\\command"); + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return NS_ERROR_FAILURE; + + nsresult rv = + regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, handlerKeyName, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) return NS_ERROR_FAILURE; + + // OK, the default value here is the description of the type. + rv = regKey->ReadStringValue(u""_ns, handlerCommand); + if (NS_FAILED(rv)) { + // Check if there is a DelegateExecute string + nsAutoString delegateExecute; + rv = regKey->ReadStringValue(u"DelegateExecute"_ns, delegateExecute); + NS_ENSURE_SUCCESS(rv, rv); + + // Look for InProcServer32 + nsAutoString delegateExecuteRegPath; + delegateExecuteRegPath.AssignLiteral("CLSID\\"); + delegateExecuteRegPath.Append(delegateExecute); + delegateExecuteRegPath.AppendLiteral("\\InProcServer32"); + rv = chkKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, + delegateExecuteRegPath, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_SUCCEEDED(rv)) { + rv = chkKey->ReadStringValue(u""_ns, handlerCommand); + } + + if (NS_FAILED(rv)) { + // Look for LocalServer32 + delegateExecuteRegPath.AssignLiteral("CLSID\\"); + delegateExecuteRegPath.Append(delegateExecute); + delegateExecuteRegPath.AppendLiteral("\\LocalServer32"); + rv = chkKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, + delegateExecuteRegPath, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + NS_ENSURE_SUCCESS(rv, rv); + rv = chkKey->ReadStringValue(u""_ns, handlerCommand); + NS_ENSURE_SUCCESS(rv, rv); + } + } + } + + // XXX FIXME: If this fails, the UI will display the full command + // string. + // There are some rare cases this can happen - ["url.dll" -foo] + // for example won't resolve correctly to the system dir. The + // subsequent launch of the helper app will work though. + nsCOMPtr<nsILocalFileWin> lf = new nsLocalFile(); + rv = lf->InitWithCommandLine(handlerCommand); + NS_ENSURE_SUCCESS(rv, rv); + lf.forget(aDefaultApplication); + + wchar_t friendlyName[1024]; + DWORD friendlyNameSize = 1024; + HRESULT hr = AssocQueryString(ASSOCF_NONE, ASSOCSTR_FRIENDLYAPPNAME, + PromiseFlatString(aAppInfo).get(), NULL, + friendlyName, &friendlyNameSize); + if (SUCCEEDED(hr) && friendlyNameSize > 1) { + aDefaultDescription.Assign(friendlyName, friendlyNameSize - 1); + } + + return NS_OK; +} + +already_AddRefed<nsMIMEInfoWin> nsOSHelperAppService::GetByExtension( + const nsString& aFileExt, const char* aTypeHint) { + if (aFileExt.IsEmpty()) return nullptr; + + // Determine the mime type. + nsAutoCString typeToUse; + if (aTypeHint && *aTypeHint) { + typeToUse.Assign(aTypeHint); + } else if (!GetMIMETypeFromOSForExtension(NS_ConvertUTF16toUTF8(aFileExt), + typeToUse)) { + return nullptr; + } + + RefPtr<nsMIMEInfoWin> mimeInfo = new nsMIMEInfoWin(typeToUse); + + // Our extension APIs expect extensions without the '.', so normalize: + uint32_t dotlessIndex = aFileExt.First() != char16_t('.') ? 0 : 1; + nsAutoCString lowerFileExt = + NS_ConvertUTF16toUTF8(Substring(aFileExt, dotlessIndex)); + ToLowerCase(lowerFileExt); + mimeInfo->AppendExtension(lowerFileExt); + mimeInfo->SetPreferredAction(nsIMIMEInfo::saveToDisk); + + if (NS_FAILED(InternalSetDefaultsOnMIME(mimeInfo))) { + return nullptr; + } + + return mimeInfo.forget(); +} + +nsresult nsOSHelperAppService::InternalSetDefaultsOnMIME( + nsMIMEInfoWin* aMIMEInfo) { + NS_ENSURE_ARG(aMIMEInfo); + + nsAutoCString primaryExt; + aMIMEInfo->GetPrimaryExtension(primaryExt); + + if (primaryExt.IsEmpty()) { + return NS_ERROR_FAILURE; + } + + // windows registry assumes your file extension is going to include the '.', + // but our APIs don't have it, so add it: + nsAutoString assocType = NS_ConvertUTF8toUTF16(primaryExt); + if (assocType.First() != char16_t('.')) { + assocType.Insert(char16_t('.'), 0); + } + + nsAutoString appInfo; + bool found; + + // Retrieve the default application for this extension + NS_ENSURE_TRUE(mAppAssoc, NS_ERROR_NOT_AVAILABLE); + wchar_t* pResult = nullptr; + HRESULT hr = mAppAssoc->QueryCurrentDefault(assocType.get(), AT_FILEEXTENSION, + AL_EFFECTIVE, &pResult); + if (SUCCEEDED(hr)) { + found = true; + appInfo.Assign(pResult); + CoTaskMemFree(pResult); + } else { + found = false; + } + + // Bug 358297 - ignore the default handler, force the user to choose app + if (appInfo.EqualsLiteral("XPSViewer.Document")) found = false; + + if (!found) { + return NS_ERROR_NOT_AVAILABLE; + } + + // Get other nsIMIMEInfo fields from registry, if possible. + nsAutoString defaultDescription; + nsCOMPtr<nsIFile> defaultApplication; + + if (NS_FAILED(GetDefaultAppInfo(appInfo, defaultDescription, + getter_AddRefs(defaultApplication)))) { + return NS_ERROR_NOT_AVAILABLE; + } + + aMIMEInfo->SetDefaultDescription(defaultDescription); + aMIMEInfo->SetDefaultApplicationHandler(defaultApplication); + + // Grab the general description + GetMIMEInfoFromRegistry(appInfo, aMIMEInfo); + return NS_OK; +} + +NS_IMETHODIMP +nsOSHelperAppService::GetMIMEInfoFromOS(const nsACString& aMIMEType, + const nsACString& aFileExt, + bool* aFound, nsIMIMEInfo** aMIMEInfo) { + *aFound = false; + + const nsCString& flatType = PromiseFlatCString(aMIMEType); + nsAutoString fileExtension; + CopyUTF8toUTF16(aFileExt, fileExtension); + + /* XXX The octet-stream check is a gross hack to wallpaper over the most + * common Win32 extension issues caused by the fix for bug 116938. See bug + * 120327, comment 271 for why this is needed. Not even sure we + * want to remove this once we have fixed all this stuff to work + * right; any info we get from the OS on this type is pretty much + * useless.... + */ + bool haveMeaningfulMimeType = + !aMIMEType.IsEmpty() && + !aMIMEType.LowerCaseEqualsLiteral(APPLICATION_OCTET_STREAM); + LOG("Extension lookup on '%S' with mimetype '%s'%s\n", + static_cast<const wchar_t*>(fileExtension.get()), flatType.get(), + haveMeaningfulMimeType ? " (treated as meaningful)" : ""); + + RefPtr<nsMIMEInfoWin> mi; + + // We should have *something* to go on here. + nsAutoString extensionFromMimeType; + if (haveMeaningfulMimeType) { + GetExtensionFromWindowsMimeDatabase(aMIMEType, extensionFromMimeType); + } + if (fileExtension.IsEmpty() && extensionFromMimeType.IsEmpty()) { + // Without an extension from the mimetype or the file, we can't + // do anything here. + mi = new nsMIMEInfoWin(flatType.get()); + mi.forget(aMIMEInfo); + return NS_OK; + } + + // Either fileExtension or extensionFromMimeType must now be non-empty. + + *aFound = true; + + // On Windows, we prefer the file extension for lookups over the mimetype, + // because that's how windows does things. + // If we have no file extension or it doesn't match the mimetype, use the + // mime type's default file extension instead. + bool usedMimeTypeExtensionForLookup = false; + if (fileExtension.IsEmpty() || + (!extensionFromMimeType.IsEmpty() && + !typeFromExtEquals(fileExtension.get(), flatType.get()))) { + usedMimeTypeExtensionForLookup = true; + fileExtension = extensionFromMimeType; + LOG("Now using '%s' mimetype's default file extension '%S' for lookup\n", + flatType.get(), static_cast<const wchar_t*>(fileExtension.get())); + } + + // If we have an extension, use it for lookup: + mi = GetByExtension(fileExtension, flatType.get()); + LOG("Extension lookup on '%S' found: 0x%p\n", + static_cast<const wchar_t*>(fileExtension.get()), mi.get()); + + if (mi) { + bool hasDefault = false; + mi->GetHasDefaultHandler(&hasDefault); + // If we don't find a default handler description, see if we can find one + // using the mimetype. + if (!hasDefault && !usedMimeTypeExtensionForLookup) { + RefPtr<nsMIMEInfoWin> miFromMimeType = + GetByExtension(extensionFromMimeType, flatType.get()); + LOG("Mime-based ext. lookup for '%S' found 0x%p\n", + static_cast<const wchar_t*>(extensionFromMimeType.get()), + miFromMimeType.get()); + if (miFromMimeType) { + nsAutoString desc; + miFromMimeType->GetDefaultDescription(desc); + mi->SetDefaultDescription(desc); + } + } + mi.forget(aMIMEInfo); + return NS_OK; + } + + // The extension didn't work. Try the extension from the mimetype if + // different: + if (!extensionFromMimeType.IsEmpty() && !usedMimeTypeExtensionForLookup) { + mi = GetByExtension(extensionFromMimeType, flatType.get()); + LOG("Mime-based ext. lookup for '%S' found 0x%p\n", + static_cast<const wchar_t*>(extensionFromMimeType.get()), mi.get()); + } + if (mi) { + mi.forget(aMIMEInfo); + return NS_OK; + } + // This didn't work either, so just return an empty dummy mimeinfo. + *aFound = false; + mi = new nsMIMEInfoWin(flatType.get()); + // If we didn't resort to the mime type's extension, we must have had a + // valid extension, so stick its lowercase version on the mime info. + if (!usedMimeTypeExtensionForLookup) { + nsAutoCString lowerFileExt; + ToLowerCase(aFileExt, lowerFileExt); + mi->AppendExtension(lowerFileExt); + } + mi.forget(aMIMEInfo); + return NS_OK; +} + +NS_IMETHODIMP +nsOSHelperAppService::UpdateDefaultAppInfo(nsIMIMEInfo* aMIMEInfo) { + InternalSetDefaultsOnMIME(static_cast<nsMIMEInfoWin*>(aMIMEInfo)); + return NS_OK; +} + +NS_IMETHODIMP +nsOSHelperAppService::GetProtocolHandlerInfoFromOS(const nsACString& aScheme, + bool* found, + nsIHandlerInfo** _retval) { + NS_ASSERTION(!aScheme.IsEmpty(), "No scheme was specified!"); + + nsresult rv = + OSProtocolHandlerExists(nsPromiseFlatCString(aScheme).get(), found); + if (NS_FAILED(rv)) return rv; + + nsMIMEInfoWin* handlerInfo = + new nsMIMEInfoWin(aScheme, nsMIMEInfoBase::eProtocolInfo); + NS_ENSURE_TRUE(handlerInfo, NS_ERROR_OUT_OF_MEMORY); + NS_ADDREF(*_retval = handlerInfo); + + if (!*found) { + // Code that calls this requires an object regardless if the OS has + // something for us, so we return the empty object. + return NS_OK; + } + + nsAutoString desc; + GetApplicationDescription(aScheme, desc); + handlerInfo->SetDefaultDescription(desc); + + return NS_OK; +} + +bool nsOSHelperAppService::GetMIMETypeFromOSForExtension( + const nsACString& aExtension, nsACString& aMIMEType) { + if (aExtension.IsEmpty()) return false; + + // windows registry assumes your file extension is going to include the '.'. + // so make sure it's there... + nsAutoString fileExtToUse; + if (aExtension.First() != '.') fileExtToUse = char16_t('.'); + + AppendUTF8toUTF16(aExtension, fileExtToUse); + + // Try to get an entry from the windows registry. + nsCOMPtr<nsIWindowsRegKey> regKey = + do_CreateInstance("@mozilla.org/windows-registry-key;1"); + if (!regKey) return false; + + nsresult rv = + regKey->Open(nsIWindowsRegKey::ROOT_KEY_CLASSES_ROOT, fileExtToUse, + nsIWindowsRegKey::ACCESS_QUERY_VALUE); + if (NS_FAILED(rv)) return false; + + nsAutoString mimeType; + if (NS_FAILED(regKey->ReadStringValue(u"Content Type"_ns, mimeType)) || + mimeType.IsEmpty()) { + return false; + } + // Content-Type is always in ASCII + aMIMEType.Truncate(); + LossyAppendUTF16toASCII(mimeType, aMIMEType); + return true; +} |