Fix MinGW builds from inside the MSYS installation tree.

 configure.ac <srcdir> [MINGW32]: Make sure the value of 'srcdir'
 is in the full /d/foo/bar form.  See the discussion in
 http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00210.html,
 and in particular
 http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00252.html
 and its followups, for the details.

2 files changed, 20 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index c075c60be23..990db8da28d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2013-09-19  Eli Zaretskii  <eliz@gnu.org>
+
+        * configure.ac <srcdir> [MINGW32]: Make sure the value of 'srcdir'
+        is in the full /d/foo/bar form.  See the discussion in
+        http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00210.html,
+        and in particular
+        http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00252.html
+        and its followups, for the details.
+
 2013-09-17  Dmitry Antipov  <dmantipov@yandex.ru>
 
         * configure.ac: Do not check for g_type_init because we
diff --git a/configure.ac b/configure.ac
index 903537f8a59..fe326623571 100644
--- a/configure.ac
+++ b/configure.ac
@@ -443,6 +443,17 @@ case "${srcdir}" in
   *  ) srcdir=`(cd "$srcdir"; pwd)` ;;
 esac
 
+#### When building with MinGW inside the MSYS tree, 'pwd' produces
+#### directories relative to the root of the MSYS tree,
+#### e.g. '/home/user/foo' instead of '/d/MSYS/home/user/foo'.  When
+#### such a value of srcdir is written to the top-level Makefile, it
+#### gets propagated to src/epaths.h, and that causes temacs to fail,
+#### because, being a MinGW program that knows nothing of MSYS root
+#### substitution, it cannot find the data directory.  "pwd -W"
+#### produces Windows-style 'd:/foo/bar' absolute directory names, so
+#### we use it here to countermand that lossage.
+test "$MSYSTEM" = "MINGW32" && srcdir=`(cd "$srcdir"; pwd -W | sed -e 's,^\([[A-Za-z]]\):,/\1,')`
+
 ### Canonicalize the configuration name.
 
 AC_CANONICAL_HOST