bug#13047: 24.2; color-hsl-to-rgb returns negative values for some inputs

[Hrvoje Niksic]

For some inputs color-hsl-to-rgb returns triplets with negative values,
which should not occur.  For example:

(color-hsl-to-rgb 0 1 0.1)
  => (0.2 0.0 -0.4)

The expected output is (0.2 0.0 0.0).


In GNU Emacs 24.2.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.6.1)
 of 2012-10-22 on eric
Configured using:
 `configure '--prefix=/usr' '--sysconfdir=/etc' '--libexecdir=/usr/lib'
 '--localstatedir=/var' '--with-x-toolkit=gtk3' '--with-xft'
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector
 --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2'
 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: C
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  savehist-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
ESC x r e p o r TAB RET

Recent messages:
("emacs")
Loading term/xterm...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
~/elisp/ido hides /usr/share/emacs/24.2/lisp/ido
~/elisp/savehist hides /usr/share/emacs/24.2/lisp/savehist
~/elisp/linum hides /usr/share/emacs/24.2/lisp/linum

Features:
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