[packages] wview: fix operation for low temperatures for WMRUSB

When the outside temperature is less than -10C the station reports that
dewpoint is invalid. This patch allows to ignore only that value instead
of ignoring all of the packet contents from the outside sensor (including
temperature and humidity).

This is also sort of fixed (the reported dew point values might be
invalid) in upstream release 5.20.0, but we can't use his repository
because there is no public repository and also he ignores requests on
his semi-private bugtracker; so we need to use the source we can
trust, and currently jgoerzen's branch is the best source out there.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@36389 3c298f89-4303-0410-b956-a3cf2f4a3e73

utils/wview/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=wview
 PKG_VERSION:=5.19.0-jgoerzen
-PKG_RELEASE=$(PKG_SOURCE_VERSION)
+PKG_RELEASE=$(PKG_SOURCE_VERSION)-r1
 PKG_SOURCE_URL:=git://github.com/jgoerzen/wview.git
 PKG_SOURCE_VERSION:=7bfac6c11e756290c38e7b5862a4c51b6bc6c51e
 PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)

utils/wview/patches/040-WMRUSB-process-absent-dewpoint.patch

@@ -0,0 +1,29 @@
+Index: wview-5.19.0-jgoerzen/stations/WMRUSB/wmrusbprotocol.c
+===================================================================
+--- wview-5.19.0-jgoerzen.orig/stations/WMRUSB/wmrusbprotocol.c	2012-12-15 15:32:03.000000000 +0000
++++ wview-5.19.0-jgoerzen/stations/WMRUSB/wmrusbprotocol.c	2012-12-15 15:36:47.199715376 +0000
+@@ -70,12 +70,9 @@
+ {
+     a &= 0xff;
+     b &= 0xff;
+-    int t = (b << 8) | a;
+-    if (t & 0x8000)
+-    {
+-        t &= 0x7FFF;
++    int t = ((b & 0x0f) << 8) | a;
++    if (b & 0x80)
+         return -(t / 10.0);
+-    }
+     else
+         return t / 10.0;
+ }
+@@ -166,6 +163,9 @@
+             return;
+         }
+ 
++        if (ptr[5] & 0x20)
++            dew = ARCHIVE_VALUE_NULL;
++
+         wmrWork.sensorData.humidity[sensor] = humid;
+         wmrWork.sensorData.temp[sensor]     = temp;
+         wmrWork.sensorData.dewpoint[sensor] = dew;