diffpkg: support multiple diff modes to compare with

This adds support for the following diff modes:

- content list (default)
- diffoscope
- .PKGINFO diff
- .BUILDINFO diff

3 files changed, 113 insertions, 11 deletions

diff --git a/diffpkg.in b/diffpkg.in
index 23c1f81..977a767 100644
--- a/diffpkg.in
+++ b/diffpkg.in
@@ -8,19 +8,32 @@ m4_include(lib/common.sh)
 
 usage() {
     cat <<- _EOF_
-		Usage: ${BASH_SOURCE[0]##*/} [OPTIONS]
+		Usage: ${BASH_SOURCE[0]##*/} [OPTIONS] [MODES]
 
 		Searches for a locally built package corresponding to the PKGBUILD, and
 		downloads the last version of that package from the Pacman repositories.
-		It then compares them with diffoscope.
+		It then compares them using different modes while using simple tar
+		content list by default.
 
 		OPTIONS
 		    -M, --makepkg-config Set an alternate makepkg configuration file
+		    -v, --verbose        Provide more detailed/unfiltered output
 		    -h, --help           Show this help text
+
+		MODES
+		    -l, --list           Activate content list diff mode (default)
+		    -d, --diffoscope     Activate diffoscope diff mode
+		    -p, --pkginfo        Activate .PKGINFO diff mode
+		    -b, --buildinfo      Activate .BUILDINFO diff mode
 _EOF_
 }
 
 MAKEPKG_CONF=/etc/makepkg.conf
+VERBOSE=0
+TARLIST=0
+DIFFOSCOPE=0
+PKGINFO=0
+BUILDINFO=0
 
 # option checking
 while (( $# )); do
@@ -33,6 +46,26 @@ while (( $# )); do
 			MAKEPKG_CONF="$2"
 			shift 2
 			;;
+		-l|--list)
+			TARLIST=1
+			shift
+			;;
+		-d|--diffoscope)
+			DIFFOSCOPE=1
+			shift
+			;;
+		-p|--pkginfo)
+			PKGINFO=1
+			shift
+			;;
+		-b|--buildinfo)
+			BUILDINFO=1
+			shift
+			;;
+		-v|--verbose)
+			VERBOSE=1
+			shift
+			;;
 		--)
 			shift
 			break
@@ -46,6 +79,10 @@ while (( $# )); do
 	esac
 done
 
+if ! (( DIFFOSCOPE || TARLIST || PKGINFO || BUILDINFO )); then
+	TARLIST=1
+fi
+
 # Source makepkg.conf; fail if it is not found
 if [[ -r "${MAKEPKG_CONF}" ]]; then
 	# shellcheck source=makepkg-x86_64.conf
@@ -75,7 +112,45 @@ fi
 
 STARTDIR=$(pwd)
 trap 'rm -rf $TEMPDIR' EXIT INT TERM QUIT
-TEMPDIR=$(mktemp -d --tmpdir diffpkg-script.XXXX)
+TEMPDIR=$(mktemp -d --tmpdir diffpkg-script.XXXXXXXX)
+
+tar_list() {
+	bsdtar tf "$*" | if (( VERBOSE )); then
+		cat
+	else
+		sed -E 's|^usr/lib/modules/[0-9][^/]+|usr/lib/modules/[…]|g'
+	fi | sort
+}
+
+diff_pkgs() {
+	local oldpkg=$1
+	local newpkg=$2
+
+	if (( TARLIST )); then
+		tar_list "$oldpkg" > "$TEMPDIR/filelist-old"
+		tar_list "$newpkg" > "$TEMPDIR/filelist"
+
+		sdiff -s "$TEMPDIR/filelist-old" "$TEMPDIR/filelist"
+	fi
+
+	if (( PKGINFO )); then
+		bsdtar xOqf "$oldpkg" .PKGINFO > "$TEMPDIR/pkginfo-old"
+		bsdtar xOqf "$newpkg" .PKGINFO > "$TEMPDIR/pkginfo"
+
+		sdiff -s "$TEMPDIR/pkginfo-old" "$TEMPDIR/pkginfo"
+	fi
+
+	if (( BUILDINFO )); then
+		bsdtar xOqf "$oldpkg" .BUILDINFO > "$TEMPDIR/buildinfo-old"
+		bsdtar xOqf "$newpkg" .BUILDINFO > "$TEMPDIR/buildinfo"
+
+		sdiff -s "$TEMPDIR/buildinfo-old" "$TEMPDIR/buildinfo"
+	fi
+
+	if (( DIFFOSCOPE )); then
+		diffoscope "$(readlink -e "$oldpkg")" "$(readlink -e "$newpkg")"
+	fi
+}
 
 for _pkgname in "${pkgname[@]}"; do
 	comparepkg=$_pkgname
@@ -121,5 +196,5 @@ for _pkgname in "${pkgname[@]}"; do
 		curl -fsLC - --retry 3 --retry-delay 3 -o "$TEMPDIR/$oldpkg" "$pkgurl"
 	fi
 
-        diffoscope $TEMPDIR/$oldpkg $pkgfile
+	diff_pkgs "$TEMPDIR/$oldpkg" "$pkgfile"
 done
diff --git a/doc/diffpkg.1.asciidoc b/doc/diffpkg.1.asciidoc
index fe11872..e95fa43 100644
--- a/doc/diffpkg.1.asciidoc
+++ b/doc/diffpkg.1.asciidoc
@@ -3,31 +3,48 @@ diffpkg(1)
 
 Name
 ----
-diffpkg - Diffoscope the current build package with the repository version
+diffpkg - Compare package files using different modes.
 
 Synopsis
 --------
-diffpkg
+diffpkg [OPTIONS] [MODES]
 
 Description
 -----------
 
 Searches for a locally built package corresponding to the PKGBUILD, and
 downloads the last version of that package from the Pacman repositories.
-It then compares them with diffoscope.
+It then compares them using different modes while using simple tar
+content list by default.
 
 Options
 -------
 
 *-M, --makepkg-config*::
-	Set an alternate makepkg configuration file.
+	Set an alternate makepkg configuration file
+
+*-v, --verbose*::
+	Provide more detailed/unfiltered output
 
 *-h, --help*::
 	Show a help text
 
+Modes
+-----
+
+*-l, --list*::
+	Activate tar content list diff mode (default)
+
+*-d, --diffoscope*::
+	Activate diffoscope diff mode
+
+*-p, --pkginfo*::
+	Activate .PKGINFO diff mode
+
+*-b, --buildinfo*::
+	Activate .BUILDINFO diff mode
+
 See Also
 --------
 
-linkman:find-libprovides[1]
-
 include::footer.asciidoc[]
diff --git a/zsh_completion.in b/zsh_completion.in
index f640086..c76e66e 100644
--- a/zsh_completion.in
+++ b/zsh_completion.in
@@ -1,4 +1,4 @@
-#compdef archbuild archco arch-nspawn archrelease commitpkg finddeps makechrootpkg mkarchroot rebuildpkgs extrapkg=commitpkg corepkg=commitpkg testingpkg=commitpkg stagingpkg=commitpkg communitypkg=commitpkg community-testingpkg=commitpkg community-stagingpkg=commitpkg multilibpkg=commitpkg multilib-testingpkg=commitpkg extra-x86_64-build=archbuild testing-x86_64-build=archbuild staging-x86_64-build=archbuild multilib-build=archbuild multilib-testing-build=archbuild multilib-staging-build=archbuild kde-unstable-x86_64-build=archbuild gnome-unstable-x86_64-build=archbuild communityco=archco checkpkg sogrep offload-build makerepropkg
+#compdef archbuild archco arch-nspawn archrelease commitpkg diffpkg finddeps makechrootpkg mkarchroot rebuildpkgs extrapkg=commitpkg corepkg=commitpkg testingpkg=commitpkg stagingpkg=commitpkg communitypkg=commitpkg community-testingpkg=commitpkg community-stagingpkg=commitpkg multilibpkg=commitpkg multilib-testingpkg=commitpkg extra-x86_64-build=archbuild testing-x86_64-build=archbuild staging-x86_64-build=archbuild multilib-build=archbuild multilib-testing-build=archbuild multilib-staging-build=archbuild kde-unstable-x86_64-build=archbuild gnome-unstable-x86_64-build=archbuild communityco=archco checkpkg sogrep offload-build makerepropkg
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -41,6 +41,16 @@ _commitpkg_args=(
 	'1:commit_msg'
 )
 
+_diffpkg_args=(
+	'(-l --list)'{-l,--list}'[Tar content list diff mode]'
+	'(-d --diffoscope)'{-d,--diffoscope}'[Diffoscope diff mode]'
+	'(-p --pkginfo)'{-p,--pkginfo}'[.PKGINFO diff mode]'
+	'(-b --buildinfo)'{-b,--buildinfo}'[.BUILDINFO diff mode]'
+	'(-m --makepkg-config)'{-m,--makepkg-config}'[Location of a makepkg config file]:makepkg_config:_files -g "*.conf(.)"'
+	'(-v --verbose)'{-v,--verbose}'[Provide more detailed/unfiltered output]'
+	'(-h --help)'{-h,--help}'[Display usage]'
+)
+
 _finddeps_args=(
 	'1:packages:_devtools_completions_all_packages'
 )