Update package version to 1.6.51

pkg.info

@@ -1,8 +1,16 @@
 name: libpng
 description: PNG formatted image file manipulation library
-version: 1.6.50
+version: 1.6.51
+revision: 1
 url: http://www.libpng.org/pub/png/libpng.html
 license: custom
 architecture: any
-depends: ["bash","zlib"]
 type: source
+depends:
+  - bash
+  - zlib
+downloads:
+  - url: https://github.com/pnggroup/libpng/archive/refs/tags/v${BPM_PKG_VERSION}.tar.gz
+    extract_to: ${BPM_SOURCE}
+    extract_strip_components: 1
+    checksum: b1872484c1c5c70acc79cbb15fb366df954fa8d5dacbe7f729d858902d17933c

source.sh

@@ -2,16 +2,6 @@
 # BPM Expects the source code to be extracted into the automatically created 'source' directory which can be accessed using $BPM_SOURCE
 # BPM Expects the output files to be present in the automatically created 'output' directory which can be accessed using $BPM_OUTPUT
 
-DOWNLOAD="https://github.com/pnggroup/libpng/archive/refs/tags/v${BPM_PKG_VERSION}.tar.gz"
-FILENAME="${DOWNLOAD##*/}"
-
-# The prepare function is executed in the root of the temp directory
-# This function is used for downloading files and putting them into the correct location
-prepare() {
-  wget "$DOWNLOAD"
-  tar -xvf "$FILENAME" --strip-components=1 -C "$BPM_SOURCE"
-}
-
 # The build function is executed in the source directory
 # This function is used to compile the source code
 build() {
@@ -30,5 +20,6 @@ check() {
 package() {
   make DESTDIR="$BPM_OUTPUT" install
 
+  # Install package license
   install -Dm644 "$BPM_SOURCE"/LICENSE "$BPM_OUTPUT"/usr/share/licenses/libpng/LICENSE
 }