From: Nick Bowler <nbowler@draconx.ca>
Date: Thu, 23 Jan 2014 01:12:02 +0000 (-0500)
Subject: tests: Zero out transparent pixels before calculating digest.
X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/commitdiff_plain/d1c92ce9f559ece233cb82425d634bf6484aff2f

tests: Zero out transparent pixels before calculating digest.

The colour value of transparent pixels is irrelevant from a correctness
perspective, but we are nevertheless including that information in the
tests.  While we could zero out the values in the PAM output code it's
better to make the tests more robust.

This adds an external dependency on netpbm's pamarith and pamchannel
tools for the test suite.  Restructure the tests so that these tools
are optional.  If the tools are not available (or not working) then we
must accept the fact that images with an alpha channel may have false
negatives (but not false positives) -- record a SKIP result for an MD5
mismatch in that case.
---

diff --git a/configure.ac b/configure.ac
index af2b64f..8a460a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-dnl Copyright © 2009, 2013 Nick Bowler
+dnl Copyright © 2009, 2013-2014 Nick Bowler
 dnl
 dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
 dnl This is free software: you are free to do what the fuck you want to.
@@ -51,12 +51,18 @@ AS_CASE([$enable_lbxgui],
 
 AM_CONDITIONAL([BUILD_LBXGUI], [$have_gtk])
 
+# Check for utilities used by the test suite.
 DX_PROG_MD5SUM
 AS_IF([test x"$dx_cv_md5sum_works" = x"yes"],
 	[AC_SUBST([HAVE_MD5SUM], [true])],
 	[AC_SUBST([HAVE_MD5SUM], [false])])
 AC_SUBST([MD5SUM])
 
+AC_CHECK_PROGS([PAMARITH], [pamarith], [false])
+AC_CHECK_PROGS([PAMCHANNEL], [pamchannel], [false])
+AC_SUBST([PAMCHANNEL])
+AC_SUBST([PAMARITH])
+
 AC_CONFIG_FILES([
 	tests/util/test-defs.sh
 	Makefile
diff --git a/tests/util/test-defs.sh.in b/tests/util/test-defs.sh.in
index d56b97c..663fdee 100644
--- a/tests/util/test-defs.sh.in
+++ b/tests/util/test-defs.sh.in
@@ -7,4 +7,7 @@ MKDIR_P='@MKDIR_P@'
 HAVE_MD5SUM='@HAVE_MD5SUM@'
 MD5SUM='@MD5SUM@'
 
+PAMCHANNEL='@PAMCHANNEL@'
+PAMARITH='@PAMARITH@'
+
 EXEEXT='@EXEEXT@'
diff --git a/tests/util/test-init.sh b/tests/util/test-init.sh
index d59b853..2c72bf3 100644
--- a/tests/util/test-init.sh
+++ b/tests/util/test-init.sh
@@ -113,20 +113,57 @@ dx_pam_header() {
 		END { exit ret }' ${1+"$@"}
 }
 
-dx_check_pam_md5_() {
+# Set all transparent pixels in a PAM image to black.  This assumes (fine for
+# LBX images) that all pixels are either fully-transparent or fully-opaque.
+dx_pam_normalize() {
 	dx_pam_header "$1" > "$1.sh" || return
-	. "./$1.sh" || return
+	( . "./$1.sh" || exit
+		case $TUPLTYPE in
+		GRAYSCALE_ALPHA) $PAMCHANNEL -infile "$1" 1 > "$1.alpha" ;;
+		RGB_ALPHA) $PAMCHANNEL -infile "$1" 3 > "$1.alpha" ;;
+		*) rm -f "$1.alpha" ;;
+		esac
+	) || return
+
+	if test -e "$1.alpha"; then
+		$PAMARITH -and "$1" "$1.alpha"
+	else
+		cat "$1"
+	fi
+}
 
-	tail -n +"$ENDHDR" "$1" > "$1.px" || return
-	echo "$2  $1.px" > "$1.md5" || return
-	$MD5SUM -c "$1.md5"
+dx_check_pam_md5_() {
+	( dx_pam_header "$1" > "$1.sh" || exit
+		. "./$1.sh" || exit
+		tail -n +"$ENDHDR" "$1" > "$1.px"
+	) || return 55
+
+	$MD5SUM -c <<EOF
+$2  $1.px
+EOF
 }
 
 dx_check_pam_md5() {
 	if $HAVE_MD5SUM; then
-		command_ok_ "$1" dx_check_pam_md5_ "$1" "$2"
+		if dx_pam_normalize "$1" > "$1.tmp"; then
+			mv -f "$1.tmp" "$1"
+			dx_md5_reliable=true
+		else
+			dx_md5_reliable=false
+		fi
+
+		dx_check_pam_md5_ "$1" "$2"
+		case $? in
+		0)  ok_ "$1" ;;
+		55) not_ok_ "$1" ;;
+		*) if $dx_md5_reliable; then
+			not_ok_ "$1"
+		else
+			skip_ -r "netpbm unavailable or broken" "$1"
+		fi ;;
+		esac
 	else
-		skip_ "$1"
+		skip_ -r "md5sum unavailable or broken" "$1"
 	fi
 }