maxima: add a subpkg maxima-ecl needed for sagemath

- Added a build option 'ecl' (enabled by default)
 - The ecl binary and library will be in a subpkg maxima-ecl so this
   should not affect current users of maxima
 - new patches:
   - a0d7a43...: build a FASL library for ECL (this is merged upstream)
   - handle-multiple-ldflags.patch: otherwise compilation with multiple
     options in LDFLAGS fails (taken from debian)
   - matrixexp.patch: fixes an error in matrix exponentiation (taken
     from debian, this originates in sagemath)

A weak point is that the library maxima.fas is installed in
/usr/lib/ecl-${ecl_version} which is where ecl looks for them, but this
doesn't seem right.

Maybe an alternative would be to have the ecl package ship a symlink at
/usr/lib/ecl pointing to the versioned directory, then have the
maxima-ecl package place its library in the non-versioned directory.

srcpkgs/maxima-ecl

@@ -0,0 +1 @@
+maxima

srcpkgs/maxima/patches/a0d7a43e5234305bd6f1de5909d4ce5d7e1ea864.patch

@@ -0,0 +1,24 @@
+commit a0d7a43e5234305bd6f1de5909d4ce5d7e1ea864
+Author: Robert Dodier <robert_dodier@users.sourceforge.net>
+Date:   Mon Oct 11 22:40:13 2021 -0700
+
+    Apply patch #80: "Build a FASL library, needed by SageMath"
+    
+    This modifies maxima.system for ECL only.
+
+diff --git a/src/maxima.system b/src/maxima.system
+index d954bc2b9..525fb778e 100644
+--- a/src/maxima.system
++++ b/src/maxima.system
+@@ -75,6 +75,11 @@
+ 			     ;; Convert dir/foo.fas to dir/foo.o
+ 			     (make-pathname :type "o" :defaults p))
+ 			 files)))
++	(c::build-fasl "binary-ecl/maxima" :lisp-files obj
++			  :ld-flags
++			  (let ((x (symbol-value (find-symbol "*AUTOCONF-LD-FLAGS*"
++							      (find-package "MAXIMA")))))
++			    (if (and x (not (string= x ""))) (list x))))
+ 	(c::build-program "binary-ecl/maxima" :lisp-files obj
+ 			  :ld-flags
+ 			  (let ((x (symbol-value (find-symbol "*AUTOCONF-LD-FLAGS*"

srcpkgs/maxima/patches/handle-multiple-ldflags.patch

@@ -0,0 +1,43 @@
+Description: Handle multiple LDFLAGS
+ Without this patch, building with LDFLAGS containing more than one flag results 
+ in flags being dropped.
+Author: Graham Inggs <ginggs@debian.org>
+Bug-Debian: http://bugs.debian.org/847925
+
+--- a/src/maxima.system
++++ b/src/maxima.system
+@@ -58,6 +58,19 @@
+     (and (apply #'compile-file file :output-file object-output args)
+ 	 (c:build-fasl output :lisp-files (list object-output)))))
+ 
++(defun split-string (string &key (item #\space) (test #'char=))
++  ;; Splits the string into substrings at spaces.
++  (let ((len (length string))
++	(index 0) result)
++    (dotimes (i len
++		(progn (unless (= index len)
++			 (push (subseq string index) result))
++		       (reverse result)))
++      (when (funcall test (char string i) item)
++	(unless (= index i);; two spaces in a row
++	  (push (subseq string index i) result))
++	(setf index (1+ i))))))
++
+ #+ecl
+ (defun build-maxima-lib ()
+   (labels ((list-all-objects (module)
+@@ -79,12 +92,12 @@
+ 			  :ld-flags
+ 			  (let ((x (symbol-value (find-symbol "*AUTOCONF-LD-FLAGS*"
+ 							      (find-package "MAXIMA")))))
+-			    (if (and x (not (string= x ""))) (list x))))
++			    (if (and x (not (string= x ""))) (split-string x))))
+ 	(c::build-program "binary-ecl/maxima" :lisp-files obj
+ 			  :ld-flags
+ 			  (let ((x (symbol-value (find-symbol "*AUTOCONF-LD-FLAGS*"
+ 							      (find-package "MAXIMA")))))
+-			    (if (and x (not (string= x ""))) (list x)))
++			    (if (and x (not (string= x ""))) (split-string x)))
+ 			  :epilogue-code '(progn (cl-user::run)))))))
+ 
+ (defun maxima-binary-pathname ()

srcpkgs/maxima/patches/matrixexp.patch

@@ -0,0 +1,23 @@
+Description: Fix error in matrix exponentiation
+ This patch was written by SageMath but not yet committed into Maxima releases.
+ However, it is needed for SageMath to work correctly:
+ .
+ https://git.sagemath.org/sage.git/tree/build/pkgs/maxima/patches/matrixexp.patch
+Author: Peter Bruin <P.J.Bruin@math.leidenuniv.nl>
+Bug-Sage: http://trac.sagemath.org/ticket/13973
+Bug: https://sourceforge.net/p/maxima/bugs/2596/
+---
+This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
+--- a/share/linearalgebra/matrixexp.lisp
++++ b/share/linearalgebra/matrixexp.lisp
+@@ -138,8 +138,8 @@
+ 	   (print `(ratvars = ,$ratvars gcd = '$gcd algebraic = ,$algebraic))
+ 	   (print `(ratfac = ,$ratfac))
+ 	   (merror "Unable to find the spectrum")))
+-   
+-    (setq res ($fullratsimp (ncpower (sub (mult z ($ident n)) mat) -1) z))
++
++    (setq res ($fullratsimp ($invert_by_lu (sub (mult z ($ident n)) mat) '$crering) z))
+     (setq m (length sp))
+     (dotimes (i m)
+       (setq zi (nth i sp))

srcpkgs/maxima/template

@@ -1,11 +1,11 @@
 # Template file for 'maxima'
 pkgname=maxima
 version=5.45.1
-revision=1
+revision=2
 build_style=gnu-configure
-configure_args="$(vopt_enable clisp) $(vopt_enable sbcl sbcl-exec)"
+configure_args="$(vopt_enable clisp) $(vopt_enable sbcl sbcl-exec) $(vopt_enable ecl)"
 hostmakedepends="python3 perl emacs texinfo"
-makedepends="$(vopt_if clisp clisp) $(vopt_if sbcl sbcl)"
+makedepends="$(vopt_if clisp clisp) $(vopt_if sbcl sbcl) $(vopt_if ecl ecl)"
 depends="$(vopt_if clisp clisp) rlwrap"
 checkdepends="gnuplot"
 short_desc="Computer Algebra System"
@@ -17,10 +17,11 @@ checksum=fe9016276970bef214a1a244348558644514d7fdfaa4fc8b9d0e87afcbb4e7dc
 
 nostrip=yes
 nopie=yes
-build_options="clisp sbcl"
+build_options="clisp sbcl ecl"
 desc_option_clisp="Build with CLISP"
 desc_option_sbcl="Build with SBCL"
-build_options_default="sbcl"
+desc_option_ecl="Build with ECL"
+build_options_default="sbcl ecl"
 vopt_conflict clisp sbcl
 
 post_install() {
@@ -66,3 +67,26 @@ xmaxima_package() {
 			${PKGDESTDIR}/usr/share/pixmaps/maxima
 	}
 }
+
+subpackages="maxima-src maxima-emacs xmaxima"
+
+if [ "$build_option_ecl" ]; then
+	subpackages+=" maxima-ecl"
+fi
+
+maxima-ecl_package() {
+	short_desc+=" - compiled with ECL"
+	depends="${sourcepkg}-${version}_${revision}"
+	pkg_install() {
+		# this is /usr/lib/ecl-${ecl_version}
+		# ideally we would just place it in /usr/lib/ecl but this
+		# doesn't just work
+		# Maybe we can have the ecl package ship a symlink:
+		#     /usr/lib/ecl -> /usr/lib/ecl-${ecl_version}
+		# and have this package just install in /usr/lib/ecl
+		ECLDIR=$(ecl -eval "(princ (SI:GET-LIBRARY-PATHNAME))" -eval "(quit)")
+		vmkdir $ECLDIR
+		vinstall src/binary-ecl/maxima.fas 755 $ECLDIR
+		vmove usr/lib/maxima/${version}/binary-ecl
+	}
+}