Rubi loops in rule50

[rwst]

My 32GB RAM Linux system killed the voracious Rubi after 30min before it was too late:

In [7]: rubi_integrate((a + b*x)**(3/2) * (c + d*x)**(1/3), x)
Killed

This part of the backtrace repeats:

~/sympy/sympy/integrals/rubi/utility_function.py in Int(expr, var)
    160 def Int(expr, var):
    161     from sympy.integrals.rubi.rubi import rubi_integrate
--> 162     return rubi_integrate(expr, var)
    163 
    164 def Set(expr, value):

~/sympy/sympy/integrals/rubi/rubi.py in rubi_integrate(expr, var, showsteps)
    203         return S(expr)*var
    204 
--> 205     result = rubi.replace(Integral(expr, var))
    206 
    207     return result

~/.pyenv/versions/3.6.3/lib/python3.6/site-packages/matchpy-0.4.5.dev22+g39dabdc.d20180419-py3.6.egg/matchpy/matching/many_to_one.py in replace(self, expression, max_count)
    795                 try:
    796                     replacement, subst = next(iter(self.matcher.match(subexpr)))
--> 797                     result = replacement(**subst)
    798                     expression = functions.replace(expression, pos, result)
    799                     replaced = True

~/sympy/sympy/integrals/rubi/rules/linear_products.py in <lambda>(d, a, b, m, x, n, c)
    256 
    257     pattern50 = Pattern(Integral((a_ + x_*WC('b', S(1)))**m_*(c_ + x_*WC('d', S(1)))**n_, x_), CustomConstraint(lambda a, x: FreeQ(a, x)), CustomConstraint(lambda b, x: FreeQ(b, x)), CustomConstraint(lambda c, x: FreeQ(c, x)), CustomConstraint(lambda d, x: FreeQ(d, x)), CustomConstraint(lambda m, x: FreeQ(m, x)), CustomConstraint(lambda n, x: FreeQ(n, x)), CustomConstraint(lambda a, c, b, d: NonzeroQ(-a*d + b*c)), CustomConstraint(lambda m: Not(IntegerQ(m))), CustomConstraint(lambda n: Not(IntegerQ(n))), CustomConstraint(lambda m, n: RationalQ(m) | Not(SimplerQ(n + S(1), m + S(1)))))
--> 258     rule50 = ReplacementRule(pattern50, lambda d, a, b, m, x, n, c : (b/(-a*d + b*c))**(-IntPart(n))*(b*(c + d*x)/(-a*d + b*c))**(-FracPart(n))*(c + d*x)**FracPart(n)*Int((a + b*x)**m*(b*c/(-a*d + b*c) + b*d*x/(-a*d + b*c))**n, x))
    259     rubi.add(rule50)
    260 

~/sympy/sympy/integrals/rubi/utility_function.py in Int(expr, var)
    160 def Int(expr, var):
    161     from sympy.integrals.rubi.rubi import rubi_integrate
--> 162     return rubi_integrate(expr, var)

When using Rubi in Mathematica the following rule matches first:

Rule 71: If NeQ[b c-a d,0]&&GtQ[n,0]&&NeQ[m+n+1,0]&&!(IGtQ[m,0]&&(!IntegerQ[n]||(GtQ[m,0]&&LtQ[m-n,0])))&&!ILtQ[m+n+2,0]&&IntLinearQ[a,b,c,d,m,n,x],

\[Integral](a+b x)^m (c+d x)^n\[DifferentialD]x \[LongRightArrow] Simp[((a+b x)^(m+1) (c+d x)^n)/(b (m+n+1)),x]+Dist[(n (b c-a d))/(b (m+n+1)),\[Integral](a+b x)^m (c+d x)^(n-1)\[DifferentialD]x,x]

(6 (a + b x)^(5/2) (c + d x)^(1/3))/(17 b) + 
 Dist[(2 (b c - a d))/(17 b), Int[(a + b x)^(3/2)/(c + d x)^(2/3), x],
   x]

[ashishkg0022]

I think this is fixed in current master

In [4]: rubi_integrate((a + b*x)**(S(3)/2) * (c + d*x)**(S(1)/3), x)
Out[4]: 6*(a + b*x)**(3/2)*(c + d*x)**(4/3)/(17*d) + 54*sqrt(a + b*x)*(c + d*x)**(4/3)*(a*d - b*c)/(187*d**2) + 162*sqrt(a + b*x)*(c + d*x)**(1/3)*(a*d - b*c)**2/(935*b*d**2) - 108*3**(3/4)*sqrt((b**(2/3)*(c + d*x)**(2/3) - b**(1/3)*(c + d*x)**(1/3)*(a*d - b*c)**(1/3) + (a*d - b*c)**(2/3))/(b**(1/3)*(c + d*x)**(1/3) + (1 + sqrt(3))*(a*d - b*c)**(1/3))**2)*sqrt(sqrt(3) + 2)*(a*d - b*c)**3*(b**(1/3)*(c + d*x)**(1/3) + (a*d - b*c)**(1/3))*elliptic_f(asin((b**(1/3)*(c + d*x)**(1/3) - (-1 + sqrt(3))*(a*d - b*c)**(1/3))/(b**(1/3)*(c + d*x)**(1/3) + (1 + sqrt(3))*(a*d - b*c)**(1/3))), -7 - 4*sqrt(3))/(935*b**(4/3)*d**3*sqrt((a*d - b*c)**(1/3)*(b**(1/3)*(c + d*x)**(1/3) + (a*d - b*c)**(1/3))/(b**(1/3)*(c + d*x)**(1/3) + (1 + sqrt(3))*(a*d - b*c)**(1/3))**2)*sqrt(a - b*c/d + b*(c + d*x)/d))