Cleanup AppVeyor Git checkout more safely.

appveyor.sh

@@ -2,12 +2,6 @@
 #
 # Cleanup for Appveyor peculiarities.
 #
-# This thing is dangerous.  See "rm -rf *".  It tries hard, but if it
-# gets it wrong you will not be happy.
-#
-# Only run this on an Appveyor instance, where the consequences are
-# nil.
-#
 
 # Echo, eval, and error on shell commands.
 eeval()
@@ -31,26 +25,12 @@ exec 0</dev/null
 # Mosh-specific environment
 export LANG=en_US.UTF-8
 
-# Make sure we're on Appveyor
-if [ -z "$APPVEYOR_BUILD_FOLDER" ]; then
-    echo "$0: APPVEYOR_BUILD_FOLDER variable empty" >&2
-    exit 2
-fi
-
-# Make really, really sure we're in the build dir
-cd $APPVEYOR_BUILD_FOLDER || exit 2
-if [ "$(pwd)" = "$HOME" -o "$PWD" = "$HOME" ]; then
-    echo "$0: in home directory" >&2
-    exit 2
-fi
-
-set -e
-
 case $1 in
     before_build)
-	# Check that we're in a Mosh repo with mosh-1.2.5, then clean it mercilessly
+	# This repo was checked out with Windows Git, repair it for Cygwin.
 	eeval git config --local core.symlinks true
-	eeval "git describe 3c3b356cb5e387887499beb2eedddce185f36944 && rm -rf * && git reset --hard"
+	eeval git clean --force --quiet -x -d
+	eeval git reset --hard
 	;;
     build_script)
 	eeval ./autogen.sh