master 00f1a4b: Get fractional seconds in iso8601 parsing right

[Lars Ingebrigtsen]

branch: master
commit 00f1a4be719cab4f1a3591ab3321ff34c86af86b
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Get fractional seconds in iso8601 parsing right
    
    * lisp/calendar/iso8601.el (iso8601-parse-time): Get fractional
    times (with leading zeroes in the fraction part) right (bug#49017).
    Fix based on a patch by "J.P." <jp@neverwas.me>.
---
 lisp/calendar/iso8601.el            | 17 +++++++++++------
 test/lisp/calendar/iso8601-tests.el | 10 +++++++++-
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/lisp/calendar/iso8601.el b/lisp/calendar/iso8601.el
index 44c4811..f22f060 100644
--- a/lisp/calendar/iso8601.el
+++ b/lisp/calendar/iso8601.el
@@ -231,17 +231,22 @@ See `decode-time' for the meaning of FORM."
                            (string-to-number (match-string 2 time))))
               (second (and (match-string 3 time)
                            (string-to-number (match-string 3 time))))
-             (fraction (and (not (zerop (length (match-string 4 time))))
-                             (string-to-number (match-string 4 time)))))
+              (frac-string (match-string 4 time))
+              fraction fraction-precision)
+          (when frac-string
+            ;; Remove trailing zeroes.
+            (setq frac-string (replace-regexp-in-string "0+\\'" "" 
frac-string))
+            (when (length> frac-string 0)
+              (setq fraction (string-to-number frac-string)
+                    fraction-precision (length frac-string))))
           (when (and fraction
                      (eq form t))
             (cond
              ;; Sub-second time.
              (second
-              (let ((digits (1+ (truncate (log fraction 10)))))
-                (setq second (cons (+ (* second (expt 10 digits))
-                                      fraction)
-                                   (expt 10 digits)))))
+              (setq second (cons (+ (* second (expt 10 fraction-precision))
+                                    fraction)
+                                 (expt 10 fraction-precision))))
              ;; Fractional minute.
              (minute
               (setq second (iso8601--decimalize fraction 60)))
diff --git a/test/lisp/calendar/iso8601-tests.el 
b/test/lisp/calendar/iso8601-tests.el
index 618e5b1..c4d038a 100644
--- a/test/lisp/calendar/iso8601-tests.el
+++ b/test/lisp/calendar/iso8601-tests.el
@@ -183,7 +183,15 @@
   (should (equal (iso8601-parse-time "15:27:35.123" t)
                  '((35123 . 1000) 27 15 nil nil nil nil -1 nil)))
   (should (equal (iso8601-parse-time "15:27:35.123456789" t)
-                 '((35123456789 . 1000000000) 27 15 nil nil nil nil -1 nil))))
+                '((35123456789 . 1000000000) 27 15 nil nil nil nil -1 nil)))
+  (should (equal (iso8601-parse-time "15:27:35.012345678" t)
+                '((35012345678 . 1000000000) 27 15 nil nil nil nil -1 nil)))
+  (should (equal (iso8601-parse-time "15:27:35.00001" t)
+                 '((3500001 . 100000) 27 15 nil nil nil nil -1 nil)))
+  (should (equal (iso8601-parse-time "15:27:35.0000100" t)
+                 '((3500001 . 100000) 27 15 nil nil nil nil -1 nil)))
+  (should (equal (iso8601-parse-time "15:27:35.0" t)
+                 '(35 27 15 nil nil nil nil -1 nil))))
 
 (ert-deftest standard-test-time-of-day-beginning-of-day ()
   (should (equal (iso8601-parse-time "000000")