calc/calc-forms.el (math-normalize-hms): Do a better check for

"negative" hms forms.

lisp/ChangeLog

+2014-09-05  Jay Belanger  <jay.p.belanger@gmail.com>
+
+	* calc/calc-forms.el (math-normalize-hms): Do a better check for
+	"negative" hms forms.
+
 2014-09-04  Rasmus Pank Roulund  <emacs@pank.eu>
 	* vc/vc-git.el (vc-git-conflicted-files): Fix bug when git status

lisp/calc/calc-forms.el

@@ -273,7 +273,10 @@
 	(m (math-normalize (nth 2 a)))
 	(s (let ((calc-internal-prec (max (- calc-internal-prec 4) 3)))
 	     (math-normalize (nth 3 a)))))
-    (if (math-negp h)
+    (if (or 
+         (math-negp h)
+         (and (= h 0) (math-negp m))
+         (and (= h 0) (= m 0) (math-negp s)))
 	(progn
 	  (if (math-posp s)
 	      (setq s (math-add s -60)