Update NETGEAR WNDR3700/3800 model string detection patch

patches/openwrt/0027-ar71xx-fix-model-string-detection-on-NETGEAR-WNDR3700-3800-WNDRMAC.patch

 From: Matthias Schiffer <mschiffer@universe-factory.net>
-Date: Sun, 15 Mar 2015 19:51:15 +0100
+Date: Sun, 29 Mar 2015 13:23:26 +0200
 Subject: ar71xx: fix model string detection on NETGEAR WNDR3700/3800/WNDRMAC
 
 There were a few issues with the existing code to detect the model string:
 * Always using the string starting with byte 56 would cut off the W of WNDR when
-  the ID starts with 29763654+16+128 instead of 29763654+16+64
+  the ID starts with 29763654+16+64 instead of 29763654+16+128
 * The string contained garbage after the zero byte instead of cutting it off
   after the zero (which wasn't always visible using busybox tools, but could
   confuse other scripts)
 
+Tested on a WNDR3700v1 and a WNDR3700v2 using the new 29763654+16+64 ID in the
+ART. Furthermore, tested against ART dumps of a WNDR3700v2 using the old
+$'\xff...' value and a WNDR3800.
+
+The [ -z "$model" ] check was dropped as there is no way to actually hit this
+unless no ART partition is found at all.
+
+The awk command was carefully crafted to work both with gawk and the (horribly
+broken) busybox awk.
+
+Fixes #18992.
+
+Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
+
 diff --git a/target/linux/ar71xx/base-files/lib/ar71xx.sh b/target/linux/ar71xx/base-files/lib/ar71xx.sh
-index a698ce5..0f9be69 100755
+index a698ce5..1838cb4 100755
 --- a/target/linux/ar71xx/base-files/lib/ar71xx.sh
 +++ b/target/linux/ar71xx/base-files/lib/ar71xx.sh
-@@ -37,16 +37,28 @@ wndr3700_board_detect() {
+@@ -37,16 +37,26 @@ wndr3700_board_detect() {
  		machine="NETGEAR WNDR3700"
  		;;
  	"33373031")
 -		local model
 -		model=$(ar71xx_get_mtd_offset_size_format art 56 10 %c)
 -		if [ -z "$model" ] || [ "$model" = $'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff' ]; then
-+		case "$(ar71xx_get_mtd_offset_size_format art 56 10 %c)" in
-+		$'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff')
- 			machine="NETGEAR WNDR3700v2"
+-			machine="NETGEAR WNDR3700v2"
 -		elif [ -z "$model" ] || [ "$model" = $'\xff\xff\xff\xff\xff\xff\xff\xff\xffN' ]; then
-+			;;
-+		$'\xff\xff\xff\xff\xff\xff\xff\xff\xffN')
- 			machine="NETGEAR WNDRMAC"
+-			machine="NETGEAR WNDRMAC"
 -		else
--			machine="NETGEAR $model"
--		fi
--		;;
++		# Use awk to remove everything after the first zero byte
++		model="$(ar71xx_get_mtd_offset_size_format art 41 32 %c | awk 'BEGIN{FS="[[:cntrl:]]"} {print $1; exit}')"
++		case $model in
++		$'\xff'*)
++			if [ "${model:24:1}" = 'N' ]; then
++				machine="NETGEAR WNDRMAC"
++			else
++				machine="NETGEAR WNDR3700v2"
++			fi
++			;;
++		'29763654+16+64'*)
++			machine="NETGEAR ${model:14}"
++			;;
++		'29763654+16+128'*)
++			machine="NETGEAR ${model:15}"
 +			;;
 +		*)
-+			# Use awk to remove everything after the first zero byte
-+			model="$(ar71xx_get_mtd_offset_size_format art 41 32 %c | awk 'BEGIN{FS="[[:cntrl:]]"} {print $1; exit}')"
-+			case $model in
-+			'29763654+16+64'*)
-+				machine="NETGEAR ${model:14}"
-+				;;
-+			'29763654+16+128'*)
-+				machine="NETGEAR ${model:15}"
-+				;;
-+			*)
-+				# Unknown ID
-+				machine="NETGEAR $model"
-+			esac
++			# Unknown ID
+ 			machine="NETGEAR $model"
+-		fi
+-		;;
 +		esac
  	esac