commit dd061664505a22fa09a1d267cfdc995244961beb
Author: eszense <eszense@users.noreply.github.com>
Date:   Thu Jan 19 20:42:39 2017 +0800

    Fix install-script execution for alt python location
    
    Without this patch, if install-script specified and
    alternative python location selected during installation,
    msiexec will faile with:
    
    "There is a problem with this Windows Installer
    package. A program required for this install to
    complete could not be run. Contact your support
    personnel or package vendor."

diff --git a/Lib/distutils/command/bdist_msi.py b/Lib/distutils/command/bdist_msi.py
index a4bd5a5..9a90fb6 100644
--- a/Lib/distutils/command/bdist_msi.py
+++ b/Lib/distutils/command/bdist_msi.py
@@ -377,6 +377,17 @@ class bdist_msi(Command):
     def add_scripts(self):
         if self.install_script:
             start = 6800
+
+            ver = self.other_version
+            exe_action = "PythonExe" + ver
+            exe_prop = "PYTHON" + ver
+            target_dir_prop = "TARGETDIR" + ver
+            add_data(self.db, "CustomAction",
+                    [(exe_action, 51, exe_prop, "[" + target_dir_prop + "]\\python.exe")])
+            add_data(self.db, "InstallExecuteSequence",
+                    [(exe_action, None, start)])
+            start += 1
+
             for ver in self.versions + [self.other_version]:
                 install_action = "install_script." + ver
                 exe_prop = "PYTHON" + ver