[gitg] Compile with -mwindows flag on windows

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 7e6ef1ee1cc7d5035a9a903759b95ebfb4d88a0c
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Tue Dec 22 18:39:54 2015 +0100

    Compile with -mwindows flag on windows

 configure.ac     |   13 +++++++++++++
 gitg/Makefile.am |    4 ++++
 2 files changed, 17 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index ea12fd5..98c7571 100644
--- a/configure.ac
+++ b/configure.ac
@@ -122,6 +122,19 @@ AM_CONDITIONAL(PLATFORM_WIN32, test x"$PLATFORM_NAME" = "xwin32")
 
 AC_DEFINE_UNQUOTED(PLATFORM_NAME,"$PLATFORM_NAME", [platform name])
 
+AC_MSG_CHECKING([for native Win32])
+case "$host" in
+       *-*-mingw*)
+               os_win32=yes
+               ;;
+       *)
+               os_win32=no
+               ;;
+esac
+
+AC_MSG_RESULT([$os_win32])
+AM_CONDITIONAL(OS_WIN32, test "$os_win32" = "yes")
+
 PKG_CHECK_MODULES(LIBGITG, [
        gthread-2.0 >= $GLIB_REQUIRED_VERSION
        glib-2.0 >= $GLIB_REQUIRED_VERSION
diff --git a/gitg/Makefile.am b/gitg/Makefile.am
index 44e2f41..00aedbc 100644
--- a/gitg/Makefile.am
+++ b/gitg/Makefile.am
@@ -47,6 +47,10 @@ gitg_gitg_LDFLAGS =                                          \
        -no-undefined                                           \
        -export-symbols-regex "^[[^_]].*"
 
+if OS_WIN32
+gitg_gitg_LDFLAGS += -mwindows
+endif
+
 gitg_gitg_VALASOURCES =                                                \
        gitg/commit/gitg-commit-dialog.vala                     \
        gitg/commit/gitg-commit-paned.vala                      \