[Buildroot] [git commit branch/next] package/pkg-generic: ensure absolute paths in config-script fixups

[Thomas Petazzoni]

commit: https://git.buildroot.net/buildroot/commit/?id=9c43f28de450adeae998d0e0d974777441510c76
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/next

In case a config script is called from a relative path, the $(dirname
$0) would return a relative path too.

Those paths are usually parts of includes or libraries search
directories, and the packagfes buildsystems may chdir() anywhere, and
thus the relative path will no longer be valid. For example:

  $ ./host/powerpc-buildroot-linux-uclibc/sysroot/usr/bin/net-snmp-config --cflags
  [...] -I./host/powerpc-buildroot-linux-uclibc/sysroot/usr/bin/../../.././bin/../powerpc-buildroot-linux-uclibc/sysroot/usr/include/libnl3 [...]

Canonicalise the path to be sure we use absolute paths.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
---
 package/pkg-generic.mk | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
index 887dc838a4..649a7ad187 100644
--- a/package/pkg-generic.mk
+++ b/package/pkg-generic.mk
@@ -280,8 +280,8 @@ $(BUILD_DIR)/%/.stamp_staging_installed:
 				-e "s,^\(exec_\)\?prefix=.*,\1prefix=@STAGING_DIR@/usr,g" \
 				-e "s,-I/usr/,-I at STAGING_DIR@/usr/,g" \
 				-e "s,-L/usr/,-L at STAGING_DIR@/usr/,g" \
-				-e 's, at STAGING_DIR@,$$(dirname $$0)/../..,g' \
-				-e 's, at HOST_DIR@,$$(dirname $$0)/../../../..,g' \
+				-e 's, at STAGING_DIR@,$$(dirname $$(realpath -e $$0))/../..,g' \
+				-e 's, at HOST_DIR@,$$(dirname $$(realpath -e $$0))/../../../..,g' \
 				-e "s, at BASE_DIR@,$(BASE_DIR),g" \
 				$(addprefix $(STAGING_DIR)/usr/bin/,$($(PKG)_CONFIG_SCRIPTS)) ;\
 	fi