From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Mon, 14 Jun 2021 13:32:03 +0000 (+0200)
Subject: Get fractional seconds in iso8601 parsing right
X-Git-Tag: emacs-28.0.90~2120
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=00f1a4be719cab4f1a3591ab3321ff34c86af86b;p=emacs.git

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>.
---

diff --git a/lisp/calendar/iso8601.el b/lisp/calendar/iso8601.el
index 44c48119845..f22f060e205 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 618e5b12386..c4d038ab68c 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")