support/dependencies: check that PATH does not contain CWD

A person on IRC reported a build failure with the util-linux package,
looking like this:

for I in uname26 linux32 linux64        ; do \
	cd /home/aep/consulting/chargery/tracker/output/target/usr/bin && ln -sf setarch $I ; \
done
[...]
/bin/sh: line 1: ./ln: cannot execute binary file: Exec format error
/bin/sh: line 1: ./ln: cannot execute binary file: Exec format error
/bin/sh: line 1: ./ln: cannot execute binary file: Exec format error

The issue was an empty path in the PATH variable, which means "current
working directory", causing a "ln" binary built by util-linux for the
target to be used instead of the system-provided "ln".

We already check a number of things in the PATH and LD_LIBRARY_PATH
variables in support/dependencies/dependencies.sh, but we were not
checking that PATH did not contain an empty path.

This commit fixes that and takes this opportunity to simplify the test
code for PATH and LD_LIBRARY_PATH.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[Thomas: improve commit log.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
index 985b1d863b0455eab0692f40868bb297b197e610..f98678973b3116287703498f7ac591d457f7327c 100755 (executable)
--- a/support/dependencies/dependencies.sh
+++ b/support/dependencies/dependencies.sh
@@ -11,27 +11,30 @@ if test $? != 0 ; then
        exit 1
 fi
 
-# sanity check for CWD in LD_LIBRARY_PATH
-# try not to rely on egrep..
-if test -n "$LD_LIBRARY_PATH" ; then
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep '::' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep ':\.:' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep 'TRiGGER_start:' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep 'TRiGGER_start\.:' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep ':TRiGGER_end' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep ':\.TRiGGER_end' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$LD_LIBRARY_PATH"TRiGGER_end | grep 'TRiGGER_start\.TRiGGER_end' >/dev/null 2>&1
-       if test $? = 0; then
-               echo
-               echo "You seem to have the current working directory in your"
-               echo "LD_LIBRARY_PATH environment variable. This doesn't work."
-               exit 1;
-       fi
-fi;
+# Sanity check for CWD in LD_LIBRARY_PATH
+case ":${LD_LIBRARY_PATH:-unset}:" in
+(*::*|*:.:*)
+       echo
+       echo "You seem to have the current working directory in your"
+       echo "LD_LIBRARY_PATH environment variable. This doesn't work."
+       exit 1
+       ;;
+esac
 
-# PATH should not contain a newline, otherwise it fails in spectacular ways
-# as soon as PATH is referenced in a package rule
-case "${PATH}" in
+# Sanity check for CWD in PATH. Having the current working directory
+# in the PATH makes various packages (e.g. toolchain, coreutils...)
+# build process break.
+# PATH should not contain a newline, otherwise it fails in spectacular
+# ways as soon as PATH is referenced in a package rule
+# An empty PATH is technically possible, but in practice we would not
+# even arrive here if that was the case.
+case ":${PATH:-unset}:" in
+(*::*|*:.:*)
+       echo
+       echo "You seem to have the current working directory in your"
+       echo "PATH environment variable. This doesn't work."
+       exit 1
+       ;;
 (*"
 "*)    printf "\n"
        # Break the '\n' sequence, or a \n is printed (which is not what we want).
@@ -41,22 +44,6 @@ case "${PATH}" in
        ;;
 esac
 
-# sanity check for CWD in PATH. Having the current working directory
-# in the PATH makes the toolchain build process break.
-# try not to rely on egrep..
-if test -n "$PATH" ; then
-       echo TRiGGER_start"$PATH"TRiGGER_end | grep ':\.:' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$PATH"TRiGGER_end | grep 'TRiGGER_start\.:' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$PATH"TRiGGER_end | grep ':\.TRiGGER_end' >/dev/null 2>&1 ||
-       echo TRiGGER_start"$PATH"TRiGGER_end | grep 'TRiGGER_start\.TRiGGER_end' >/dev/null 2>&1
-       if test $? = 0; then
-               echo
-               echo "You seem to have the current working directory in your"
-               echo "PATH environment variable. This doesn't work."
-               exit 1;
-       fi
-fi;
-
 if test -n "$PERL_MM_OPT" ; then
        echo
        echo "You have PERL_MM_OPT defined because Perl local::lib"