Consolidate #RGB string parsers

Use a single parser of color strings in the #RGB, rgb:R/G/B and
rgbi:R/G/B formats, replacing four existing ones.  Previously,
error-checking was spotty, handling of the rgbi: format not always
present, and normalization of the result was sometimes incorrect.

* src/dispextern.h: New prototype.
* src/xfaces.c (parse_hex_color_comp, parse_float_color_comp)
(parse_color_spec, Finternal-color_values_from_color_spec): New functions.
* test/src/xfaces-tests.el (xfaces-internal-color-values-from-color-spec):
New test.
* lisp/term/tty-colors.el (tty-color-standard-values):
Use internal-color-values-from-color-spec, replacing old parser.
* src/nsterm.m (ns_get_color):
* src/w32fns.c (x_to_w32_color):
* src/xterm.c (x_parse_color): Use parse_color_spec, replacing old
parsers.
(HEX_COLOR_NAME_LENGTH): Remove #define.

1 files changed, 2 insertions, 56 deletions

diff --git a/lisp/term/tty-colors.el b/lisp/term/tty-colors.el
index 39ca2d36276..73e2431822e 100644
--- a/lisp/term/tty-colors.el
+++ b/lisp/term/tty-colors.el
@@ -923,62 +923,8 @@ The returned value reflects the standard Emacs definition of
 COLOR (see the info node `(emacs) Colors'), regardless of whether
 the terminal can display it, so the return value should be the
 same regardless of what display is being used."
-  (let ((len (length color)))
-    (cond ((and (>= len 4) ;; HTML/CSS/SVG-style "#XXYYZZ" color spec
-                (eq (aref color 0) ?#)
-                (member (aref color 1)
-                        '(?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9
-                             ?a ?b ?c ?d ?e ?f
-                             ?A ?B ?C ?D ?E ?F)))
-           ;; Translate the string "#XXYYZZ" into a list of numbers
-           ;; (XX YY ZZ), scaling each to the {0..65535} range.  This
-           ;; follows the HTML color convention, where both "#fff" and
-           ;; "#ffffff" represent the same color, white.
-           (let* ((ndig (/ (- len 1) 3))
-                  (maxval (1- (ash 1 (* 4 ndig))))
-                  (i1 1)
-                  (i2 (+ i1 ndig))
-                  (i3 (+ i2 ndig))
-                  (i4 (+ i3 ndig)))
-             (list
-              (/ (* (string-to-number
-                     (substring color i1 i2) 16)
-                    65535)
-                 maxval)
-              (/ (* (string-to-number
-                     (substring color i2 i3) 16)
-                    65535)
-                 maxval)
-              (/ (* (string-to-number
-                     (substring color i3 i4) 16)
-                    65535)
-                 maxval))))
-          ((and (>= len 9) ;; X-style rgb:xx/yy/zz color spec
-                (string= (substring color 0 4) "rgb:"))
-           ;; Translate the string "rgb:XX/YY/ZZ" into a list of
-           ;; numbers (XX YY ZZ), scaling each to the {0..65535}
-           ;; range.  "rgb:F/F/F" is white.
-           (let* ((ndig (/ (- len 3) 3))
-                  (maxval (1- (ash 1 (* 4 (- ndig 1)))))
-                  (i1 4)
-                  (i2 (+ i1 ndig))
-                  (i3 (+ i2 ndig))
-                  (i4 (+ i3 ndig)))
-             (list
-              (/ (* (string-to-number
-                     (substring color i1 (- i2 1)) 16)
-                    65535)
-                 maxval)
-              (/ (* (string-to-number
-                     (substring color i2 (- i3 1)) 16)
-                    65535)
-                 maxval)
-              (/ (* (string-to-number
-                     (substring color i3 (1- i4)) 16)
-                    65535)
-                 maxval))))
-          (t
-           (cdr (assoc color color-name-rgb-alist))))))
+  (or (internal-color-values-from-color-spec color)
+      (cdr (assoc color color-name-rgb-alist))))
 
 (defun tty-color-translate (color &optional frame)
   "Given a color COLOR, return the index of the corresponding TTY color.