Fix trig simplification crash (bug#33052)

* lisp/calc/calc-alg.el (calcFunc-sec, calcFunc-csc, calcFunc-cot):
Check that `math-known-sin' and `math-known-tan' succeeded before
using their value in arithmetic.
* test/lisp/calc/calc-tests.el (calc-test-trig): Add regression tests.
Backport from master.

1 files changed, 12 insertions, 6 deletions

diff --git a/lisp/calc/calc-alg.el b/lisp/calc/calc-alg.el
index 8e3476d191e..b41749ca775 100644
--- a/lisp/calc/calc-alg.el
+++ b/lisp/calc/calc-alg.el
@@ -847,11 +847,13 @@
       (and (eq calc-angle-mode 'rad)
            (let ((n (math-linear-in (nth 1 math-simplify-expr) '(var pi var-pi))))
              (and n
-                  (math-div 1 (math-known-sin (car n) (nth 1 n) 120 300)))))
+                  (let ((s (math-known-sin (car n) (nth 1 n) 120 300)))
+                    (and s (math-div 1 s))))))
       (and (eq calc-angle-mode 'deg)
            (let ((n (math-integer-plus (nth 1 math-simplify-expr))))
              (and n
-                  (math-div 1 (math-known-sin (car n) (nth 1 n) '(frac 2 3) 300)))))
+                  (let ((s (math-known-sin (car n) (nth 1 n) '(frac 2 3) 300)))
+                    (and s (math-div 1 s))))))
       (and (eq (car-safe (nth 1 math-simplify-expr)) 'calcFunc-arcsin)
            (math-div
             1
@@ -872,11 +874,13 @@
       (and (eq calc-angle-mode 'rad)
            (let ((n (math-linear-in (nth 1 math-simplify-expr) '(var pi var-pi))))
              (and n
-                  (math-div 1 (math-known-sin (car n) (nth 1 n) 120 0)))))
+                  (let ((s (math-known-sin (car n) (nth 1 n) 120 0)))
+                    (and s (math-div 1 s))))))
       (and (eq calc-angle-mode 'deg)
            (let ((n (math-integer-plus (nth 1 math-simplify-expr))))
              (and n
-                  (math-div 1 (math-known-sin (car n) (nth 1 n) '(frac 2 3) 0)))))
+                  (let ((s (math-known-sin (car n) (nth 1 n) '(frac 2 3) 0)))
+                    (and s (math-div 1 s))))))
       (and (eq (car-safe (nth 1 math-simplify-expr)) 'calcFunc-arcsin)
            (math-div 1 (nth 1 (nth 1 math-simplify-expr))))
       (and (eq (car-safe (nth 1 math-simplify-expr)) 'calcFunc-arccos)
@@ -977,11 +981,13 @@
       (and (eq calc-angle-mode 'rad)
            (let ((n (math-linear-in (nth 1 math-simplify-expr) '(var pi var-pi))))
              (and n
-                  (math-div 1 (math-known-tan (car n) (nth 1 n) 120)))))
+                  (let ((tn (math-known-tan (car n) (nth 1 n) 120)))
+                    (and tn (math-div 1 tn))))))
       (and (eq calc-angle-mode 'deg)
            (let ((n (math-integer-plus (nth 1 math-simplify-expr))))
              (and n
-                  (math-div 1 (math-known-tan (car n) (nth 1 n) '(frac 2 3))))))
+                  (let ((tn (math-known-tan (car n) (nth 1 n) '(frac 2 3))))
+                    (and tn (math-div 1 tn))))))
       (and (eq (car-safe (nth 1 math-simplify-expr)) 'calcFunc-arcsin)
            (math-div (list 'calcFunc-sqrt
                            (math-sub 1 (math-sqr (nth 1 (nth 1 math-simplify-expr)))))