[Rd] qgamma with first argument 1

[J. Hosking]

   > qgamma(1,1.1)
   [1] Inf

as expected.  But for shape parameter between 0.16 and 1:

   > qgamma(1,.5)
   [1] NaN
   Warning message:
   NaNs produced in: qgamma(p, shape, scale, lower.tail, log.p)

and for shape parameter 0.16 or less:

   > qgamma(1,.1)
   [1] 99.42507

Arguments close to 1 give approximately correct results:

   > qgamma(1-1e-15,.5)
   [1] 32.05055
   > qgamma(1-1e-15,.1)
   [1] 28.8129





R version is the R 2.1.1 binary from CRAN:
   platform i386-pc-mingw32
   arch     i386
   os       mingw32
   system   i386, mingw32
   status
   major    2
   minor    1.1
   year     2005
   month    06
   day      20
   language R