From 73737231b95976f24b7b9bff96240976b11dcce0 Mon Sep 17 00:00:00 2001
From: "W. Felix Handte" <w@felixhandte.com>
Date: Tue, 18 Feb 2020 13:17:17 -0500
Subject: [PATCH] Allow Manual Overriding of pkg-config Lib and Include Dirs

When the `PCLIBDIR` or `PCINCDIR` is non-empty (either because we succeeded
in removing the prefix, or because it was manually set), we don't need to
perform the check. This lets us trust users who go to the trouble of setting
a manual override, rather than still blindly failing the make.

They'll still be prefixed with `${prefix}/` / `${exec_prefix}/` in the
pkg-config file though.
---
 lib/Makefile | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/Makefile b/lib/Makefile
index dbd64994c..b067c11a2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -227,12 +227,21 @@ INCLUDEDIR  ?= $(includedir)
 PCLIBDIR ?= $(shell echo "$(LIBDIR)" | sed -n -e "s@^$(exec_prefix)\\(/\\|$$\\)@@p")
 PCINCDIR ?= $(shell echo "$(INCLUDEDIR)" | sed -n -e "s@^$(prefix)\\(/\\|$$\\)@@p")
 
+ifeq (,$(PCLIBDIR))
+# Additional prefix check is required, since the empty string is technically a
+# valid PCLIBDIR
 ifeq (,$(shell echo "$(LIBDIR)" | sed -n -e "\\@^$(exec_prefix)\\(/\\|$$\\)@ p"))
 $(error configured libdir ($(LIBDIR)) is outside of prefix ($(prefix)), can't generate pkg-config file)
 endif
+endif
+
+ifeq (,$(PCINCDIR))
+# Additional prefix check is required, since the empty string is technically a
+# valid PCINCDIR
 ifeq (,$(shell echo "$(INCLUDEDIR)" | sed -n -e "\\@^$(prefix)\\(/\\|$$\\)@ p"))
 $(error configured includedir ($(INCLUDEDIR)) is outside of exec_prefix ($(exec_prefix)), can't generate pkg-config file)
 endif
+endif
 
 ifneq (,$(filter $(shell uname),FreeBSD NetBSD DragonFly))
 PKGCONFIGDIR ?= $(PREFIX)/libdata/pkgconfig