From d8c8d51386e00c157fa77fc2792bbf86d3c6cbe3 Mon Sep 17 00:00:00 2001
From: sledgehammer999 <hammered999@gmail.com>
Date: Sun, 14 Sep 2014 21:49:52 +0300
Subject: [PATCH] WINDOWS: Can now correctly detect 64bit and 32bit python
 installations on 64bit Windows. Closes #1148 #445 #795 #1708.

Conflicts:
	src/preferences/preferences.cpp
---
 src/preferences/preferences.h | 99 +++++++++++++++++++++++++----------
 1 file changed, 70 insertions(+), 29 deletions(-)

diff --git a/src/preferences/preferences.h b/src/preferences/preferences.h
index 76ed6929c..7e9d3c650 100755
--- a/src/preferences/preferences.h
+++ b/src/preferences/preferences.h
@@ -1223,37 +1223,17 @@ public:
 
 #ifdef Q_WS_WIN
   static QString getPythonPath() {
-    HKEY key_handle1;
-    long res = ::RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Python\\PythonCore"), 0, KEY_READ, &key_handle1);
-    if (res == ERROR_SUCCESS) {
-      QStringList versions = getRegSubkeys(key_handle1);
-      qDebug("Python versions nb: %d", versions.size());
-      versions.sort();
+    QString path = pythonSearchReg(USER);
+    if (path.isEmpty())
+      path = pythonSearchReg(SYSTEM_32BIT);
+    else return path;
 
-      while(!versions.empty()) {
-        const QString version = versions.takeLast()+"\\InstallPath";
-        HKEY key_handle2;
-        LPTSTR subkey = new TCHAR[version.size()+1];
-        version.toWCharArray(subkey);
-        subkey[version.size()] = '\0';
+    if (path.isEmpty())
+      path = pythonSearchReg(SYSTEM_64BIT);
+    else return path;
 
-        res = ::RegOpenKeyEx(key_handle1, subkey, 0, KEY_READ, &key_handle2);
-        delete[] subkey;
-        if (res == ERROR_SUCCESS) {
-          qDebug("Detected possible Python v%s location", qPrintable(version));
-          QString path = getRegValue(key_handle2);
-          ::RegCloseKey(key_handle2);
-          if (!path.isEmpty() && QDir(path).exists("python.exe")) {
-            qDebug("Found python.exe at %s", qPrintable(path));
-            ::RegCloseKey(key_handle1);
-            return path;
-          }
-        }
-        else
-          ::RegCloseKey(key_handle2);
-      }
-    }
-    ::RegCloseKey(key_handle1);
+    if (!path.isEmpty())
+      return path;
 
     // Fallback: Detect python from default locations
     QStringList supported_versions;
@@ -1402,6 +1382,8 @@ public:
 
 #ifdef Q_OS_WIN
 private:
+  enum REG_SEARCH_TYPE {USER, SYSTEM_32BIT, SYSTEM_64BIT};
+  
   static QStringList getRegSubkeys(const HKEY &handle) {
     QStringList keys;
     DWORD subkeys_count = 0;
@@ -1456,6 +1438,65 @@ private:
 
     return end_result;
   }
+
+  static QString pythonSearchReg(const REG_SEARCH_TYPE type) {
+    HKEY key_handle1;
+    long res = 0;
+
+    switch (type) {
+    case USER:
+      res = ::RegOpenKeyEx(HKEY_CURRENT_USER, TEXT("SOFTWARE\\Python\\PythonCore"), 0, KEY_READ, &key_handle1);
+      break;
+    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);
+      qDebug("Python versions nb: %d", versions.size());
+      versions.sort();
+
+      while(!versions.empty()) {
+        const QString version = versions.takeLast()+"\\InstallPath";
+        HKEY key_handle2;
+        LPTSTR subkey = new TCHAR[version.size()+1];
+        version.toWCharArray(subkey);
+        subkey[version.size()] = '\0';
+
+        switch (type) {
+        case USER:
+          res = ::RegOpenKeyEx(key_handle1, subkey, 0, KEY_READ, &key_handle2);
+          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);
+          ::RegCloseKey(key_handle2);
+          if (!path.isEmpty() && QDir(path).exists("python.exe")) {
+            qDebug("Found python.exe at %s", qPrintable(path));
+            ::RegCloseKey(key_handle1);
+            return path;
+          }
+        }
+        else
+          ::RegCloseKey(key_handle2);
+      }
+    }
+    ::RegCloseKey(key_handle1);
+    return QString::null;
+  }
 #endif
 };