python2: Fix sys.prefix in a Cygwin friendly way

The same issue is can be reproduced on Cygwin so re-implement
the msys2-specific fix using cygwin_conv_path() instead.

python2/0260-fix-sys-prefix-when-win-drive-in-argv0.patch

@@ -1,28 +1,40 @@
 diff -urN Python-2.7.10.orig/Modules/getpath.c Python-2.7.10/Modules/getpath.c
---- Python-2.7.10.orig/Modules/getpath.c	2015-07-06 13:16:43.261177500 +0100
-+++ Python-2.7.10/Modules/getpath.c	2015-07-06 13:17:53.505177500 +0100
-@@ -229,8 +229,20 @@
+--- Python-2.7.10.orig/Modules/getpath.c	2015-07-07 12:58:16.162926800 +0100
++++ Python-2.7.10/Modules/getpath.c	2015-07-07 13:09:22.496926800 +0100
+@@ -10,6 +10,10 @@
+ #include <mach-o/dyld.h>
+ #endif
+ 
++#ifdef __CYGWIN__
++#include <sys/cygwin.h>
++#endif
++
+ /* Search in some common locations for the associated Python libraries.
+  *
+  * Two directories must be found, the platform independent directory
+@@ -229,8 +233,21 @@
  static void
  copy_absolute(char *path, char *p)
  {
-+#if defined(__MSYS__)
-+    if (p[0] == SEP || (p[0] != '\0' && p[1] == ':'))
++#if defined(__CYGWIN__)
++    int win_drive = (p[0] != '\0' && p[1] == ':') ? 1 : 0;
++    if (p[0] == SEP || win_drive)
 +#else
      if (p[0] == SEP)
 +#endif
          strcpy(path, p);
-+#if defined(__MSYS__)
-+        /* Turn C:* into /c* since sys.path can't have drive seps (:) in
-+           since those delimit path list entries. */
-+        if (path[0] != '\0' && path[1] == ':') {
-+            path[1]=tolower(path[0]);
-+            path[0]='/';
++#if defined(__CYGWIN__)
++        /* Turn absolute paths with Windows drive letters into their
++           Cygwin equivalent since sys.path can't have drive seps (:)
++           in since those delimit path list entries */
++        if (win_drive) {
++            cygwin_conv_path(CCP_WIN_A_TO_POSIX, p, path, MAXPATHLEN + 1);
 +        }
 +#endif
      else {
          if (!getcwd(path, MAXPATHLEN)) {
              /* unable to get the current directory */
-@@ -482,7 +494,11 @@
+@@ -482,7 +499,11 @@
          }
          else
                  progpath[0] = '\0';

python2/PKGBUILD

@@ -3,7 +3,7 @@
 
 pkgname=python2
 pkgver=2.7.10
-pkgrel=2
+pkgrel=3
 _pybasever=2.7
 pkgdesc="A high-level scripting language"
 arch=('i686' 'x86_64')
@@ -45,7 +45,7 @@ sha1sums=('ee5a50c5562e7448f037d35fdedc18d95c748b9e'
           'a1806da6956df1860cc23ff3701cd80cbb126b87'
           'e6e13cb541efaaf228355cb1d7d5cd8574757c72'
           '80975639f5ad78fd15b8f81bd98fb460c4ee05c4'
-          '6aa9ec9e99b75725a2f4de681ea8dbd0b2cad2e6')
+          '6f3a97afc9bb1a688010241203b9598f34a47eea')
 
 prepare() {
   cd "${srcdir}/Python-${pkgver}"