Use most recent snapshot file

Author: jdemeyer

.travis-install-pari.sh

@@ -8,7 +8,9 @@ PARI_URL="http://pari.math.u-bordeaux.fr/pub/pari/$URLDIR"
 # Figure out PARI version and download location
 # Note that we support giving a list of URLs
 if [ "$PARI_VERSION" = snapshot ]; then
-    PARI_VERSION=$(wget -qO- "$PARI_URL" | sed -n 's/.*href="\(pari-.*-g.*\)[.]tar[.]gz".*/\1/p')
+    # The C=M;O=D request means: sort by date, most recent first.
+    # Then the first tarball is the one we want.
+    PARI_VERSION=$(wget -qO- "$PARI_URL/?C=M;O=D" | sed -n 's/.*href="\(pari-.*-g.*\)[.]tar[.]gz".*/\1/; T; p; q')
 fi
 
 # Download PARI sources