From ea63da3e7da922165e52038d8acbb2f01aa7c8e6 Mon Sep 17 00:00:00 2001
From: Valentin Lorentz <progval@progval.net>
Date: Fri, 11 Jan 2013 18:14:11 +0100
Subject: [PATCH] Math: As unit conversion algorithm fails with high precision,
 make significant digits matter.

---
 plugins/Math/plugin.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/plugins/Math/plugin.py b/plugins/Math/plugin.py
index 8c5bbae6f..92949fb30 100644
--- a/plugins/Math/plugin.py
+++ b/plugins/Math/plugin.py
@@ -308,9 +308,19 @@ class Math(callbacks.Plugin):
         Converts from <unit> to <other unit>. If number isn't given, it
         defaults to 1. For unit information, see 'units' command.
         """
+        try:
+            digits = len(str(number).split('.')[1])
+        except IndexError:
+            digits = 0
         try:
             newNum = convertcore.convert(number, unit1, unit2)
             newNum = self._floatToString(newNum)
+            if isinstance(newNum, float):
+                # Let's add one signifiant digit. Physicists would not like
+                # that, but common people usually do not give extra zeros...
+                # (for example, with '32 C to F', an extra digit would be
+                # expected).
+                newNum = round(newNum, digits+1)
             irc.reply(str(newNum))
         except convertcore.UnitDataError, ude:
             irc.error(str(ude))