t/lib-httpd: refactor "one-time-perl" CGI script to not depend on Perl

Our Apache HTTPD setup exposes an "one_time_perl" endpoint to access
repositories. If used, we execute the "apply-one-time-perl.sh" CGI
script that checks whether we have a "one-time-perl" script. If so, that
script gets executed so that it can munge what would be served. Once
done, the script gets removed so that it doesn't execute a second time.

As the name says, this functionality expects the user to pass a Perl
script. This isn't really necessary though: we can just as easily
implement the same thing with arbitrary scripts.

Refactor the code so that we instead expect an arbitrary script to
exist and rename the functionality to "one-time-script". Adapt callers
to use shell utilities instead of Perl so that we can drop the
PERL_TEST_HELPERS prerequisite.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

t/lib-httpd.sh

@@ -165,7 +165,7 @@ prepare_httpd() {
 	install_script broken-smart-http.sh
 	install_script error-smart-http.sh
 	install_script error.sh
-	install_script apply-one-time-perl.sh
+	install_script apply-one-time-script.sh
 	install_script nph-custom-auth.sh
 
 	ln -s "$LIB_HTTPD_MODULE_PATH" "$HTTPD_ROOT_PATH/modules"

t/lib-httpd/apache.conf

@@ -135,7 +135,7 @@ SetEnv PERL_PATH ${PERL_PATH}
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
-<LocationMatch /one_time_perl/>
+<LocationMatch /one_time_script/>
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
@@ -159,7 +159,7 @@ ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error_smart/ error-smart-http.sh/
 ScriptAlias /error/ error.sh/
-ScriptAliasMatch /one_time_perl/(.*) apply-one-time-perl.sh/$1
+ScriptAliasMatch /one_time_script/(.*) apply-one-time-script.sh/$1
 ScriptAliasMatch /custom_auth/(.*) nph-custom-auth.sh/$1
 <Directory ${GIT_EXEC_PATH}>
 	Options FollowSymlinks
@@ -182,7 +182,7 @@ ScriptAliasMatch /custom_auth/(.*) nph-custom-auth.sh/$1
 <Files error.sh>
   Options ExecCGI
 </Files>
-<Files apply-one-time-perl.sh>
+<Files apply-one-time-script.sh>
 	Options ExecCGI
 </Files>
 <Files ${GIT_EXEC_PATH}/git-http-backend>

t/lib-httpd/apply-one-time-perl.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+# If "one-time-script" exists in $HTTPD_ROOT_PATH, run the script on the HTTP
+# response. If the response was modified as a result, delete "one-time-script"
+# so that subsequent HTTP responses are no longer modified.
+#
+# This can be used to simulate the effects of the repository changing in
+# between HTTP request-response pairs.
+if test -f one-time-script
+then
+	LC_ALL=C
+	export LC_ALL
+
+	"$GIT_EXEC_PATH/git-http-backend" >out
+	./one-time-script out >out_modified
+
+	if cmp -s out out_modified
+	then
+		cat out
+	else
+		cat out_modified
+		rm one-time-script
+	fi
+else
+	"$GIT_EXEC_PATH/git-http-backend"
+fi

t/lib-httpd/apply-one-time-script.sh

@@ -256,7 +256,7 @@ start_httpd
 
 REPO="$HTTPD_DOCUMENT_ROOT_PATH/repo"
 
-test_expect_success PERL_TEST_HELPERS 'shallow fetches check connectivity before writing shallow file' '
+test_expect_success 'shallow fetches check connectivity before writing shallow file' '
 	rm -rf "$REPO" client &&
 
 	git init "$REPO" &&
@@ -271,22 +271,21 @@ test_expect_success PERL_TEST_HELPERS 'shallow fetches check connectivity before
 	git -C "$REPO" config protocol.version 2 &&
 	git -C client config protocol.version 2 &&
 
-	git -C client fetch --depth=2 "$HTTPD_URL/one_time_perl/repo" main:a_branch &&
+	git -C client fetch --depth=2 "$HTTPD_URL/one_time_script/repo" main:a_branch &&
 
 	# Craft a situation in which the server sends back an unshallow request
 	# with an empty packfile. This is done by refetching with a shorter
 	# depth (to ensure that the packfile is empty), and overwriting the
 	# shallow line in the response with the unshallow line we want.
-	printf "$(test_oid perl)" \
-	       "$(git -C "$REPO" rev-parse HEAD)" \
-	       "$(git -C "$REPO" rev-parse HEAD^)" \
-	       >"$HTTPD_ROOT_PATH/one-time-perl" &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-EOF &&
+	sed "$(printf "$(test_oid perl)" "$(git -C "$REPO" rev-parse HEAD)" "$(git -C "$REPO" rev-parse HEAD^)")" "\$1"
+	EOF
 	test_must_fail env GIT_TEST_SIDEBAND_ALL=0 git -C client \
-		fetch --depth=1 "$HTTPD_URL/one_time_perl/repo" \
+		fetch --depth=1 "$HTTPD_URL/one_time_script/repo" \
 		main:a_branch &&
 
-	# Ensure that the one-time-perl script was used.
-	! test -e "$HTTPD_ROOT_PATH/one-time-perl" &&
+	# Ensure that the one-time-script script was used.
+	! test -e "$HTTPD_ROOT_PATH/one-time-script" &&
 
 	# Ensure that the resulting repo is consistent, despite our failure to
 	# fetch.

t/t5537-fetch-shallow.sh

@@ -737,21 +737,25 @@ intersperse () {
 	sed 's/\(..\)/'$1'\1/g'
 }
 
-# Create a one-time-perl command to replace the existing packfile with $1.
+# Create a one-time-script command to replace the existing packfile with $1.
 replace_packfile () {
-	# The protocol requires that the packfile be sent in sideband 1, hence
-	# the extra \x01 byte at the beginning.
-	cp $1 "$HTTPD_ROOT_PATH/one-time-pack" &&
-	echo 'if (/packfile/) {
-		print;
-		my $length = -s "one-time-pack";
-		printf "%04x\x01", $length + 5;
-		print `cat one-time-pack` . "0000";
-		last
-	}' >"$HTTPD_ROOT_PATH/one-time-perl"
+	cp "$1" one-time-pack &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-EOF
+	if grep packfile "\$1" >/dev/null
+	then
+		sed '/packfile/q' "\$1" &&
+		# The protocol requires that the packfile be sent in sideband
+		# 1, hence the extra \001 byte at the beginning.
+		printf "%04x\001" \$((\$(wc -c <"$PWD/one-time-pack") + 5)) &&
+		cat "$PWD/one-time-pack" &&
+		printf "0000"
+	else
+		cat "\$1"
+	fi
+	EOF
 }
 
-test_expect_success PERL_TEST_HELPERS 'upon cloning, check that all refs point to objects' '
+test_expect_success 'upon cloning, check that all refs point to objects' '
 	SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server" &&
 	rm -rf "$SERVER" repo &&
 	test_create_repo "$SERVER" &&
@@ -776,15 +780,15 @@ test_expect_success PERL_TEST_HELPERS 'upon cloning, check that all refs point t
 	# section header.
 	test_config -C "$SERVER" protocol.version 2 &&
 	test_must_fail git -c protocol.version=2 clone \
-		--filter=blob:none $HTTPD_URL/one_time_perl/server repo 2>err &&
+		--filter=blob:none $HTTPD_URL/one_time_script/server repo 2>err &&
 
 	test_grep "did not send all necessary objects" err &&
 
-	# Ensure that the one-time-perl script was used.
-	! test -e "$HTTPD_ROOT_PATH/one-time-perl"
+	# Ensure that the one-time-script script was used.
+	! test -e "$HTTPD_ROOT_PATH/one-time-script"
 '
 
-test_expect_success PERL_TEST_HELPERS 'when partial cloning, tolerate server not sending target of tag' '
+test_expect_success 'when partial cloning, tolerate server not sending target of tag' '
 	SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server" &&
 	rm -rf "$SERVER" repo &&
 	test_create_repo "$SERVER" &&
@@ -818,11 +822,11 @@ test_expect_success PERL_TEST_HELPERS 'when partial cloning, tolerate server not
 
 	# Exercise to make sure it works.
 	git -c protocol.version=2 clone \
-		--filter=blob:none $HTTPD_URL/one_time_perl/server repo 2> err &&
+		--filter=blob:none $HTTPD_URL/one_time_script/server repo 2> err &&
 	! grep "missing object referenced by" err &&
 
-	# Ensure that the one-time-perl script was used.
-	! test -e "$HTTPD_ROOT_PATH/one-time-perl"
+	# Ensure that the one-time-script script was used.
+	! test -e "$HTTPD_ROOT_PATH/one-time-script"
 '
 
 test_expect_success PERL_TEST_HELPERS 'tolerate server sending REF_DELTA against missing promisor objects' '
@@ -845,7 +849,7 @@ test_expect_success PERL_TEST_HELPERS 'tolerate server sending REF_DELTA against
 
 	# Clone. The client has deltabase_have but not deltabase_missing.
 	git -c protocol.version=2 clone --no-checkout \
-		--filter=blob:none $HTTPD_URL/one_time_perl/server repo &&
+		--filter=blob:none $HTTPD_URL/one_time_script/server repo &&
 	git -C repo hash-object -w -- "$SERVER/have.txt" &&
 
 	# Sanity check to ensure that the client does not have
@@ -899,8 +903,8 @@ test_expect_success PERL_TEST_HELPERS 'tolerate server sending REF_DELTA against
 	grep "want $(cat deltabase_missing)" trace &&
 	! grep "want $(cat deltabase_have)" trace &&
 
-	# Ensure that the one-time-perl script was used.
-	! test -e "$HTTPD_ROOT_PATH/one-time-perl"
+	# Ensure that the one-time-script script was used.
+	! test -e "$HTTPD_ROOT_PATH/one-time-script"
 '
 
 # DO NOT add non-httpd-specific tests here, because the last part of this

t/t5616-partial-clone.sh

@@ -1120,7 +1120,7 @@ test_expect_success 'push with http:// and a config of v2 does not request v2' '
 	! grep "git< version 2" log
 '
 
-test_expect_success PERL_TEST_HELPERS 'when server sends "ready", expect DELIM' '
+test_expect_success 'when server sends "ready", expect DELIM' '
 	rm -rf "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" http_child &&
 
 	git init "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
@@ -1132,15 +1132,16 @@ test_expect_success PERL_TEST_HELPERS 'when server sends "ready", expect DELIM'
 
 	# After "ready" in the acknowledgments section, pretend that a FLUSH
 	# (0000) was sent instead of a DELIM (0001).
-	printf "\$ready = 1 if /ready/; \$ready && s/0001/0000/" \
-		>"$HTTPD_ROOT_PATH/one-time-perl" &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-\EOF &&
+	sed "/ready/{n;s/0001/0000/;}" "$1"
+	EOF
 
 	test_must_fail git -C http_child -c protocol.version=2 \
-		fetch "$HTTPD_URL/one_time_perl/http_parent" 2> err &&
+		fetch "$HTTPD_URL/one_time_script/http_parent" 2> err &&
 	test_grep "expected packfile to be sent after .ready." err
 '
 
-test_expect_success PERL_TEST_HELPERS 'when server does not send "ready", expect FLUSH' '
+test_expect_success 'when server does not send "ready", expect FLUSH' '
 	rm -rf "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" http_child log &&
 
 	git init "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
@@ -1157,12 +1158,13 @@ test_expect_success PERL_TEST_HELPERS 'when server does not send "ready", expect
 
 	# After the acknowledgments section, pretend that a DELIM
 	# (0001) was sent instead of a FLUSH (0000).
-	printf "\$ack = 1 if /acknowledgments/; \$ack && s/0000/0001/" \
-		>"$HTTPD_ROOT_PATH/one-time-perl" &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-\EOF &&
+	sed "/acknowledgments/,//{s/0000/0001/;}" "$1"
+	EOF
 
 	test_must_fail env GIT_TRACE_PACKET="$(pwd)/log" git -C http_child \
 		-c protocol.version=2 \
-		fetch "$HTTPD_URL/one_time_perl/http_parent" 2> err &&
+		fetch "$HTTPD_URL/one_time_script/http_parent" 2> err &&
 	grep "fetch< .*acknowledgments" log &&
 	! grep "fetch< .*ready" log &&
 	test_grep "expected no other sections to be sent after no .ready." err
@@ -1446,14 +1448,15 @@ test_expect_success 'http:// --negotiate-only' '
 	grep "$COMMON" out
 '
 
-test_expect_success PERL_TEST_HELPERS 'http:// --negotiate-only without wait-for-done support' '
+test_expect_success 'http:// --negotiate-only without wait-for-done support' '
 	SERVER="server" &&
-	URI="$HTTPD_URL/one_time_perl/server" &&
+	URI="$HTTPD_URL/one_time_script/server" &&
 
 	setup_negotiate_only "$SERVER" "$URI" &&
 
-	echo "s/ wait-for-done/ xxxx-xxx-xxxx/" \
-		>"$HTTPD_ROOT_PATH/one-time-perl" &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-\EOF &&
+	sed "s/ wait-for-done/ xxxx-xxx-xxxx/" "$1"
+	EOF
 
 	test_must_fail git -c protocol.version=2 -C client fetch \
 		--no-tags \

t/t5702-protocol-v2.sh

@@ -468,7 +468,7 @@ test_expect_success 'setup repos for change-while-negotiating test' '
 		test_commit m3 &&
 		git tag -d m2 m3
 	) &&
-	git -C "$LOCAL_PRISTINE" remote set-url origin "http://127.0.0.1:$LIB_HTTPD_PORT/one_time_perl/repo" &&
+	git -C "$LOCAL_PRISTINE" remote set-url origin "http://127.0.0.1:$LIB_HTTPD_PORT/one_time_script/repo" &&
 	git -C "$LOCAL_PRISTINE" config protocol.version 2
 '
 
@@ -481,7 +481,9 @@ inconsistency () {
 	# RPCs during a single negotiation.
 	oid1=$(git -C "$REPO" rev-parse $1) &&
 	oid2=$(git -C "$REPO" rev-parse $2) &&
-	echo "s/$oid1/$oid2/" >"$HTTPD_ROOT_PATH/one-time-perl"
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-EOF
+	sed "s/$oid1/$oid2/" "\$1"
+	EOF
 }
 
 test_expect_success 'server is initially ahead - no ref in want' '
@@ -533,7 +535,9 @@ test_expect_success 'server loses a ref - ref in want' '
 	git -C "$REPO" config uploadpack.allowRefInWant true &&
 	rm -rf local &&
 	cp -r "$LOCAL_PRISTINE" local &&
-	echo "s/main/rain/" >"$HTTPD_ROOT_PATH/one-time-perl" &&
+	write_script "$HTTPD_ROOT_PATH/one-time-script" <<-\EOF &&
+	sed "s/main/rain/" "$1"
+	EOF
 	test_must_fail git -C local fetch 2>err &&
 
 	test_grep "fatal: remote error: unknown ref refs/heads/rain" err