gnucash maint: Handle very large denominators in precies from Finance::Quote

[Mike Alexander]

Updated	 via  https://github.com/Gnucash/gnucash/commit/0c21ae35 (commit)
	from  https://github.com/Gnucash/gnucash/commit/e13644df (commit)



commit 0c21ae35221b49c640d1025d66ea024e24db15c2
Author: Mike Alexander <mta at umich.edu>
Date:   Mon Aug 30 03:09:23 2021 -0400

    Handle very large denominators in precies from Finance::Quote
    
    The OpenExchange exchange rate source in Finance::Quote produces
    some ridiculously precise prices like #e6.95253159056541e-5 which
    produce a denominator greater than INT64_MAX.  Use the rationalize
    function to bring them back to reality.

diff --git a/gnucash/price-quotes.scm b/gnucash/price-quotes.scm
index 2c6375585..8e3ff255f 100644
--- a/gnucash/price-quotes.scm
+++ b/gnucash/price-quotes.scm
@@ -346,7 +346,13 @@
           (cond
            ((assq-ref quote-data (car price-syms)) =>
             (lambda (p)
-              (set! price (gnc-scm-to-numeric p))
+              ;; The OpenExchange exchange rate source in Finance::Quote produces
+              ;; some ridiculously precise prices like #e6.95253159056541e-5 which 
+              ;; produce a denominator greater than INT64_MAX.  Use the rationalize
+              ;; function to bring them back to reality.  The precision parameter is
+              ;; chosen empirically to give the best results.
+              (set! price (gnc-scm-to-numeric 
+                            (rationalize p 1/100000000000000)))
               (set! price-type (car price-types))))
            (else (lp (cdr price-syms) (cdr price-types))))))
 



Summary of changes:
 gnucash/price-quotes.scm | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)