bug#12687: 24.2.50; calc volume units conversion

bug#12687: 24.2.50; calc volume units conversion

[Edmund Kademan]

emacs -Q
C-x **    ;start calc
'gal RET  ;enter 1 gallon
uc        ;try to convert to new units

At this point calc should prompt for new units, but it does not.

A workaround for me is to redefine the math-get-standard-units
function:

*** calc-units.el	2012-10-19 17:35:54.000000000 -0400
--- calc-units-changed.el	2012-10-19 18:14:30.000000000 -0400
***************
*** 383,390 ****
  
  (defun math-get-standard-units (expr)
    "Return the standard units in EXPR."
!   (math-simplify-units
!    (math-extract-units
      (math-to-standard-units expr nil))))
  
  (defun math-get-units (expr)
--- 383,390 ----
  
  (defun math-get-standard-units (expr)
    "Return the standard units in EXPR."
!   (math-extract-units
!    (math-simplify-units
      (math-to-standard-units expr nil))))
  
  (defun math-get-units (expr)


In GNU Emacs 24.2.50.1 (i686-pc-linux-gnu, GTK+ Version 2.24.10)
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bug#12687: 24.2.50; calc volume units conversion

[Jay Belanger]

> emacs -Q
> C-x **    ;start calc
> 'gal RET  ;enter 1 gallon
> uc        ;try to convert to new units
>
> At this point calc should prompt for new units, but it does not.

Oh; thanks for catching this!

> A workaround for me is to redefine the math-get-standard-units
> function:

That works for this case (but for the wrong reasons ... for example, if
you convert gallons to liters and then convert gallons again, it won't
offer liters as a default).  The problem was that `math-extract-units'
wasn't dealing with powers of units (and the standard units for volume
are m^3).  This has been fixed in bzr.

Thanks again,
Jay