5 files changed, 81 insertions, 2 deletions
diff --git a/MANUAL.txt b/MANUAL.txt
index 10487a3..053bb5f 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -755,7 +755,8 @@ specification with one of these strings.
 	Executes the script using a built-in Lua interpreter. The script is
 	loaded once per execution of cgit, and may be called multiple times
 	during cgit's lifetime, making it a good choice for repeated filters
-	such as the 'email filter'. It responds to three functions:
+	such as the 'email filter'. A cgit built with NO_LUA has no interpreter
+	and refuses a filter with this prefix. It responds to three functions:
 
 	'filter_open(argument1, argument2, argument3, ...)'::
 		This is called upon activation of the filter for a particular
diff --git a/Makefile b/Makefile
index 29489b0..53580f3 100644
--- a/Makefile
+++ b/Makefile
@@ -76,10 +76,19 @@ cgit:
 	+@$(MAKE) -C $(GITDIR) -f $(CGIT_ROOT)/$(SRCDIR)/cgit.mk \
 		$(CGIT_ROOT)/$(BUILDDIR)/cgit $(EXTRA_GIT_TARGETS) $(GIT_BUILD_FLAGS)
 
+# The same program without Lua, built beside the full one so a change cannot
+# break that configuration unnoticed. The suite runs both.
+cgit-nolua:
+	+@$(MAKE) -C $(GITDIR) -f $(CGIT_ROOT)/$(SRCDIR)/cgit.mk \
+		$(CGIT_ROOT)/$(BUILDDIR)/nolua/cgit NO_LUA=1 BUILDDIR=$(BUILDDIR)/nolua $(GIT_BUILD_FLAGS)
+
 sparse:
 	+@$(MAKE) -C $(GITDIR) -f $(CGIT_ROOT)/$(SRCDIR)/cgit.mk $(GIT_BUILD_FLAGS) cgit-sparse
 
+# The two builds share the Git tree, so they are made one after the other
+# even under -j.
 test: cgit-with-git
+	+@$(MAKE) cgit-nolua
 	+@$(MAKE) -C tests all
 
 # The test helpers link against a fully built Git tree, so this asks the sub
@@ -119,6 +128,6 @@ tags:
 	@mkdir -p $(BUILDDIR)
 	find $(SRCDIR) -name '*.[ch]' | xargs ctags -f $(BUILDDIR)/tags
 
-.PHONY: all cgit cgit-with-git sparse test
+.PHONY: all cgit cgit-with-git cgit-nolua sparse test
 .PHONY: install uninstall
 .PHONY: clean cleanall get-git tags
diff --git a/README.txt b/README.txt
index 844b6d0..5582164 100644
--- a/README.txt
+++ b/README.txt
@@ -46,6 +46,11 @@ runtime, turn it off.
 
     $ make NO_LUA=1
 
+A binary built this way still runs every exec: filter, but a filter named with
+the lua: prefix has no interpreter to run in, so it is refused with an error on
+every page until the setting is taken out of cgitrc. make test builds this
+variant as well, into build/nolua, and checks it the same way.
+
 
 Setup
 -----
diff --git a/source/filter.c b/source/filter.c
index f5fb2d5..dd1eaf0 100644
--- a/source/filter.c
+++ b/source/filter.c
@@ -444,8 +444,10 @@ void cgit_abort_filters(void)
 		close(running_exec->old_stdout);
 		running_exec = NULL;
 	}
+#ifndef NO_LUA
 	if (filter_write)
 		unhook_write();
+#endif
 }
 
 static const struct {
@@ -503,5 +505,9 @@ struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
 			return filter_specs[i].create(colon + 1, argument_count);
 	}
 
+#ifdef NO_LUA
+	if (len == 3 && !strncmp("lua", cmd, len))
+		die("Built without Lua, cannot run filter %s", cmd);
+#endif
 	die("Invalid filter type: %.*s", (int)len, cmd);
 }
diff --git a/tests/t0006-nolua.sh b/tests/t0006-nolua.sh
new file mode 100755
index 0000000..c315e41
--- /dev/null
+++ b/tests/t0006-nolua.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+# The build without Lua has to serve pages like the full one and run the exec
+# filters, and a filter written with the lua: prefix has to be refused with a
+# message naming the cause. make test builds it into build/nolua beside the
+# ordinary binary. The shared cgitrc may itself name lua filters, so every
+# request here carries a config of its own.
+
+test_description='Check the build without Lua'
+. ./setup.sh
+
+nolua="$TEST_OUTPUT_DIRECTORY/../build/nolua/cgit"
+test -x "$nolua" || {
+	skip_all='Skipping the Lua-less checks: build/nolua/cgit is missing, run make test'
+	test_done
+	exit
+}
+
+nolua_query() { CGIT_CONFIG="$PWD/$1" QUERY_STRING="$2" "$nolua"; }
+
+test_expect_success 'the binary reports no Lua' '
+	"$nolua" --version >tmp &&
+	grep -F "[-] Lua scripting" tmp
+'
+
+test_expect_success 'it serves a page' '
+	{
+		echo "virtual-root=/" &&
+		echo "cache-size=0" &&
+		echo "repo.url=foo" &&
+		echo "repo.path=$PWD/repos/foo/.git"
+	} >plainrc &&
+	nolua_query plainrc "url=foo/log/" >tmp &&
+	grep "^Status: 200" tmp &&
+	grep ">commit 5</a>" tmp
+'
+
+test_expect_success 'an exec filter still runs' '
+	{
+		cat plainrc &&
+		echo "repo.commit-filter=exec:$FILTER_DIRECTORY/dump.sh"
+	} >execrc &&
+	nolua_query execrc "url=foo/commit/" >tmp &&
+	grep "COMMIT 5" tmp
+'
+
+test_expect_success 'a lua filter is refused with one error page' '
+	{
+		cat plainrc &&
+		echo "repo.commit-filter=lua:$FILTER_DIRECTORY/dump.lua"
+	} >luarc &&
+	nolua_query luarc "url=foo/commit/" >tmp 2>err &&
+	grep "^Status: 500" tmp &&
+	test $(grep -c "^Status:" tmp) = 1 &&
+	grep "Built without Lua" err
+'
+
+test_done