Trac #30319: Upgrade cddlib to fix wrong intersection of polytopes

As reported in [[https://groups.google.com/forum/#!topic/sage-
devel/514hUpM7pBY | this sage-devel thread]], the intersection of
polytopes is sometimes very wrong
{{{
a = Polyhedron([[0, -1, 1], [1, -1, 1], [1, 1, -1]])
b = Polyhedron([[0.0, -0.5, 1.5], [1.0, -0.5, 1.5], [1.0, 1.5, -0.5]])
c = a.intersection(b)
}}}
Here `c` should have been empty but is equal to `b`.

We fix it by upgrading to cddlib 0.94m, installing symlinks so that
consumers of cddlib that have not been updated to work with the new
header file locations (#29413) continue to work.

URL: https://trac.sagemath.org/30319
Reported by: vdelecroix
Ticket author(s): Jonathan Kliem, Matthias Koeppe
Reviewer(s): Matthias Koeppe, Dima Pasechnik

Author: Release Manager

build/pkgs/cddlib/checksums.ini

@@ -1,5 +1,5 @@
 tarball=cddlib-VERSION.tar.gz
-sha1=4bad24b32d9c056615377ff3103e6b95e17628ac
-md5=73e5f7dfa72b5c3339c09564721813d6
-cksum=3211115816
+sha1=8f38597a0479a191a62346dab89794e888c478b6
+md5=ec7f35912e34232b5306a643f99b6311
+cksum=2420656558
 upstream_url=https://github.com/cddlib/cddlib/releases/download/VERSION/cddlib-VERSION.tar.gz

build/pkgs/cddlib/package-version.txt

@@ -1 +1 @@
-0.94j
+0.94m

build/pkgs/cddlib/spkg-configure.m4

@@ -16,14 +16,39 @@ SAGE_SPKG_CONFIGURE([cddlib], [
     AC_CHECK_PROGS(SCDD, [scdd_gmp scdd])
     AS_IF([test x$SCDD = x], [sage_spkg_install_cddlib=yes])
 
-    dnl Future versions (>= 0.94k) of cddlib will put these headers in
+    dnl https://trac.sagemath.org/ticket/30319
+    AS_IF([test -n "$CDDEXEC"], [
+        AC_MSG_CHECKING([whether $CDDEXEC --redcheck works correctly for real input])
+        cat > conftest.ine <<EOF
+H-representation
+linearity 2 1 2
+begin
+ 5 4 real
+ 0.0 0.0 1.0 1.0
+ -1.0 0.0 1.0 1.0
+ -1.0 2.0 -1.0 0.0
+ -1.0 4.0 -2.0 0.0
+ 1 0 0 0
+end
+EOF
+        rm -f conftest.out
+        $CDDEXEC --redcheck <conftest.ine >conftest.out 2>& AS_MESSAGE_LOG_FD
+        AS_IF([grep -q "^Redundant rows.*1" conftest.out 2>& AS_MESSAGE_LOG_FD], [
+            AC_MSG_RESULT([no])
+            sage_spkg_install_cddlib=yes
+        ], [
+            AC_MSG_RESULT([yes])
+        ])
+    ])
+    dnl Recent versions (>= 0.94k) of cddlib put these headers in
     dnl a "cddlib" subdirectory, and Debian currently relocates them
     dnl under "cdd". But for now they're at the top-level, in e.g.
     dnl /usr/include/cdd.h. The lattE and gfan packages within
     dnl SageMath both look for them there, so that's where we have to
     dnl check, passing up a chance to detect cddlib on Fedora and Debian
     dnl for now. Once all of cddlib's consumers know about the new (or
     dnl both) locations, we can update this check to support them.
+    dnl See https://trac.sagemath.org/ticket/29413
     AC_CHECK_HEADER([cdd.h],[],[sage_spkg_install_cddlib=yes],[
       #include <setoper.h>
       #include <cddmp.h>

build/pkgs/cddlib/spkg-install.in

@@ -5,3 +5,10 @@ cd src
 sdh_configure
 sdh_make
 sdh_make_install
+
+# Old versions of cddlib install headers without the official prefix "cddlib/";
+# and some distributions install the headers with a prefix "cdd/".
+# We install symlinks to shadow possible system installations of these headers.
+# This can be removed as soon as all packages that detect cddlib have been
+# updated to check the official prefix "cddlib/" first.
+(cd $SAGE_DESTDIR$SAGE_LOCAL/include/ && ln -sf cddlib cdd && ln -sf cddlib/*.h .)