Merge pull request #2378 from glassez/python_reg

Improve Windows Registry searching for Python.

src/preferences/preferences.cpp

@@ -1339,134 +1339,138 @@ void Preferences::disableRecursiveDownload(bool disable) {
 
 #ifdef Q_OS_WIN
 namespace {
-enum REG_SEARCH_TYPE {USER, SYSTEM_32BIT, SYSTEM_64BIT};
+enum REG_SEARCH_TYPE
+{
+    USER,
+    SYSTEM_32BIT,
+    SYSTEM_64BIT
+};
 
-QStringList getRegSubkeys(const HKEY &handle) {
+QStringList getRegSubkeys(HKEY handle)
+{
     QStringList keys;
-  DWORD subkeys_count = 0;
+
-  DWORD max_subkey_len = 0;
+    DWORD cSubKeys = 0;
-  long res = ::RegQueryInfoKey(handle, NULL, NULL, NULL, &subkeys_count, &max_subkey_len, NULL, NULL, NULL, NULL, NULL, NULL);
+    DWORD cMaxSubKeyLen = 0;
+    LONG res = ::RegQueryInfoKeyW(handle, NULL, NULL, NULL, &cSubKeys, &cMaxSubKeyLen, NULL, NULL, NULL, NULL, NULL, NULL);
+
     if (res == ERROR_SUCCESS) {
-    max_subkey_len++; //For null character
+        cMaxSubKeyLen++; // For null character
-    LPTSTR key_name = new TCHAR[max_subkey_len];
+        LPWSTR lpName = new WCHAR[cMaxSubKeyLen];
+        DWORD cName;
 
-    for (uint i=0; i<subkeys_count; i++) {
+        for (DWORD i = 0; i < cSubKeys; ++i) {
-      res = ::RegEnumKeyEx(handle, 0, key_name, &max_subkey_len, NULL, NULL, NULL, NULL);
+            cName = cMaxSubKeyLen;
+            res = ::RegEnumKeyExW(handle, 0, lpName, &cName, NULL, NULL, NULL, NULL);
             if (res == ERROR_SUCCESS)
-        keys.push_back(QString::fromWCharArray(key_name));
+                keys.push_back(QString::fromWCharArray(lpName));
         }
-    delete[] key_name;
+
+        delete[] lpName;
     }
 
     return keys;
 }
 
-QString getRegValue(const HKEY &handle, const QString &name = QString()) {
+QString getRegValue(HKEY handle, const QString &name = QString())
-  QString end_result;
+{
-  DWORD type = 0;
+    QString result;
-  DWORD size = 0;
-  DWORD array_size = 0;
 
-  LPTSTR value_name = NULL;
+    DWORD type = 0;
+    DWORD cbData = 0;
+    LPWSTR lpValueName = NULL;
     if (!name.isEmpty()) {
-    value_name = new TCHAR[name.size()+1];
+        lpValueName = new WCHAR[name.size() + 1];
-    name.toWCharArray(value_name);
+        name.toWCharArray(lpValueName);
-    value_name[name.size()] = '\0';
+        lpValueName[name.size()] = 0;
     }
 
     // Discover the size of the value
-  ::RegQueryValueEx(handle, value_name, NULL, &type, NULL, &size);
+    ::RegQueryValueExW(handle, lpValueName, NULL, &type, NULL, &cbData);
-  array_size = size / sizeof(TCHAR);
+    DWORD cBuffer = (cbData / sizeof(WCHAR)) + 1;
-  if (size % sizeof(TCHAR))
+    LPWSTR lpData = new WCHAR[cBuffer];
-    array_size++;
+    LONG res = ::RegQueryValueExW(handle, lpValueName, NULL, &type, (LPBYTE)lpData, &cbData);
-  array_size++; //For null character
+    if (lpValueName)
-  LPTSTR value = new TCHAR[array_size];
+        delete[] lpValueName;
-
+
-  long res = ::RegQueryValueEx(handle, value_name, NULL, &type, (LPBYTE)value, &size);
     if (res == ERROR_SUCCESS) {
-    value[array_size] = '\0';
+        lpData[cBuffer - 1] = 0;
-    end_result = QString::fromWCharArray(value);
+        result = QString::fromWCharArray(lpData);
     }
+    delete[] lpData;
 
-  if (value_name)
+    return result;
-    delete[] value_name;
-  if (value)
-    delete[] value;
-
-  return end_result;
 }
 
-QString pythonSearchReg(const REG_SEARCH_TYPE type) {
+QString pythonSearchReg(const REG_SEARCH_TYPE type)
-  HKEY key_handle1;
+{
-  long res = 0;
+    HKEY hkRoot;
+    if (type == USER)
+        hkRoot = HKEY_CURRENT_USER;
+    else
+        hkRoot = HKEY_LOCAL_MACHINE;
+
+    REGSAM samDesired = KEY_READ;
+    if (type == SYSTEM_32BIT)
+        samDesired |= KEY_WOW64_32KEY;
+    else if (type == SYSTEM_64BIT)
+        samDesired |= KEY_WOW64_64KEY;
 
-  switch (type) {
+    QString path;
-  case USER:
+    LONG res = 0;
-    res = ::RegOpenKeyEx(HKEY_CURRENT_USER, TEXT("SOFTWARE\\Python\\PythonCore"), 0, KEY_READ, &key_handle1);
+    HKEY hkPythonCore;
-    break;
+    res = ::RegOpenKeyExW(hkRoot, L"SOFTWARE\\Python\\PythonCore", 0, samDesired, &hkPythonCore);
-  case SYSTEM_32BIT:
-    res = ::RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Python\\PythonCore"), 0, KEY_READ|KEY_WOW64_32KEY, &key_handle1);
-    break;
-  case SYSTEM_64BIT:
-    res = ::RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Python\\PythonCore"), 0, KEY_READ|KEY_WOW64_64KEY, &key_handle1);
-    break;
-  }
 
     if (res == ERROR_SUCCESS) {
-    QStringList versions = getRegSubkeys(key_handle1);
+        QStringList versions = getRegSubkeys(hkPythonCore);
         qDebug("Python versions nb: %d", versions.size());
         versions.sort();
 
-    while(!versions.empty()) {
+        bool found = false;
-      const QString version = versions.takeLast()+"\\InstallPath";
+        while(!found && !versions.empty()) {
-      HKEY key_handle2;
+            const QString version = versions.takeLast() + "\\InstallPath";
-      LPTSTR subkey = new TCHAR[version.size()+1];
+            LPWSTR lpSubkey = new WCHAR[version.size() + 1];
-      version.toWCharArray(subkey);
+            version.toWCharArray(lpSubkey);
-      subkey[version.size()] = '\0';
+            lpSubkey[version.size()] = 0;
-
+
-      switch (type) {
+            HKEY hkInstallPath;
-      case USER:
+            res = ::RegOpenKeyExW(hkPythonCore, lpSubkey, 0, samDesired, &hkInstallPath);
-        res = ::RegOpenKeyEx(key_handle1, subkey, 0, KEY_READ, &key_handle2);
+            delete[] lpSubkey;
-        break;
-      case SYSTEM_32BIT:
-        res = ::RegOpenKeyEx(key_handle1, subkey, 0, KEY_READ|KEY_WOW64_32KEY, &key_handle2);
-        break;
-      case SYSTEM_64BIT:
-        res = ::RegOpenKeyEx(key_handle1, subkey, 0, KEY_READ|KEY_WOW64_64KEY, &key_handle2);
-        break;
-      }
 
-      delete[] subkey;
             if (res == ERROR_SUCCESS) {
                 qDebug("Detected possible Python v%s location", qPrintable(version));
-        QString path = getRegValue(key_handle2);
+                path = getRegValue(hkInstallPath);
-        ::RegCloseKey(key_handle2);
+                ::RegCloseKey(hkInstallPath);
+
                 if (!path.isEmpty() && QDir(path).exists("python.exe")) {
                     qDebug("Found python.exe at %s", qPrintable(path));
-          ::RegCloseKey(key_handle1);
+                    found = true;
-          return path;
                 }
             }
-      else
-        ::RegCloseKey(key_handle2);
         }
+
+        if (!found)
+            path = QString();
+
+        ::RegCloseKey(hkPythonCore);
     }
-  ::RegCloseKey(key_handle1);
+
-  return QString::null;
+    return path;
 }
 
 }
 
-QString Preferences::getPythonPath() {
+QString Preferences::getPythonPath()
+{
     QString path = pythonSearchReg(USER);
-  if (path.isEmpty())
+    if (!path.isEmpty())
+        return path;
+
     path = pythonSearchReg(SYSTEM_32BIT);
-  else return path;
+    if (!path.isEmpty())
+        return path;
 
-  if (path.isEmpty())
     path = pythonSearchReg(SYSTEM_64BIT);
-  else return path;
-
     if (!path.isEmpty())
         return path;
 
@@ -1474,10 +1478,11 @@ QString Preferences::getPythonPath() {
     QStringList supported_versions;
     supported_versions << "32" << "31" << "30" << "27" << "26" << "25";
     foreach (const QString &v, supported_versions) {
-    if (QFile::exists("C:/Python"+v+"/python.exe"))
+        if (QFile::exists("C:/Python" + v + "/python.exe"))
-      return "C:/Python"+v;
+            return "C:/Python" + v;
     }
-  return QString::null;
+
+    return QString();
 }
 
 bool Preferences::neverCheckFileAssoc() const {