WIP #939 Solve returns completely wrong result

Author: axkr

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/RootsFunctions.java

@@ -771,11 +771,11 @@ private static IASTAppendable unitPolynomial(int varDegree, ExprPolynomial polyn
       }
       IExpr zDenominator;
       if (rhsDenominator.isTimes()) {
-        IASTMutable temp = rhsDenominator.mapThread(F.Power(F.Slot1, F.QQ(-1, varDegree)), 1);
         if (rhsDenominator.first().isNegative()) {
           isNegative = !isNegative;
-          temp.set(1, rhsDenominator.first().negate());
+          rhsDenominator = ((IAST) rhsDenominator).setAtCopy(1, rhsDenominator.first().negate());
         }
+        IASTMutable temp = rhsDenominator.mapThread(F.Power(F.Slot1, F.QQ(-1, varDegree)), 1);
         zDenominator = EvalEngine.get().evaluate(temp);
       } else {
         if (rhsDenominator.isNegative()) {

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/SolveTest.java

@@ -2043,6 +2043,16 @@ public void testIssue919() {
         "{{x->1125899906842624*Sqrt(1635/5747513123739563366932509455047)}}");
   }
 
+  @Test
+  public void testIssue939() {
+    check("Solve(8000 ==60*(x^3/32*Pi),x)", //
+        "{{x->(8*(-5)^(2/3))/(3*Pi)^(1/3)},{x->(8*5^(2/3))/(3*Pi)^(1/3)},{x->(-8*(-1)^(1/\n"
+            + "3)*5^(2/3))/(3*Pi)^(1/3)}}");
+    check("Solve(8000/(x^3/32*Pi)==60,x)", //
+        "{{x->(8*(-5)^(2/3))/(3*Pi)^(1/3)},{x->(8*5^(2/3))/(3*Pi)^(1/3)},{x->(-8*(-1)^(1/\n"
+            + "3)*5^(2/3))/(3*Pi)^(1/3)}}");
+  }
+
   /** The JUnit setup method */
   @Override
   public void setUp() {