From 99f293b4147dd4ac3fe131f0d0ac0a1d3681e5f6 Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Sun, 28 Feb 2021 10:49:00 -0700
Subject: [PATCH] install.sh: add installation preconditions check

As the last step before actually starting to do the install,
add a preconditions check phase.

Currently the only check is that the Markdown module can
be used and that it produces the expected output on a very
tiny test case.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
---
 install.sh | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/install.sh b/install.sh
index 35abb48..51eb2b7 100755
--- a/install.sh
+++ b/install.sh
@@ -575,6 +575,23 @@ case "$cfg_cgiroot" in /*) :;; *)
 	exit 1
 esac
 
+echo "*** Verifying installation preconditions..."
+
+# Make sure Markdown.pm is present and use'able
+if
+	! [ -e Markdown.pm ] || ! [ -f Markdown.pm ] || ! [ -s Markdown.pm ] ||
+	! mdoutput="$("$perlbin" 2>/dev/null -I"$PWD" -MMarkdown=Markdown,ProcessRaw -e \
+		'use strict; use warnings; print Markdown("_test_ **this**"); exit 0;')"
+then
+	echo "ERROR: markdown.git is not checked out! Did you _REALLY_ read INSTALL?" >&2
+	exit 1
+fi
+# And that it at least appears to function properly
+if [ "$mdoutput" != '<p><em>test</em> <strong>this</strong></p>' ]; then
+	echo "ERROR: markdown.git verification test failed -- Markdown function does not work" >&2
+	exit 1
+fi
+
 # return the input with trailing slashes stripped but return "/" for all "/"s
 striptrsl() {
 	[ -n "$1" ] || return 0
-- 
2.11.4.GIT