tests: avoid FP of ls/stat-free-color.sh with newer glibc

Since glibc-2.22, specifically commit [0], the opendir() implementation
implicitly makes an additional stat call thus leading to a FP.
Seen on openSUSE:Tumbleweed since snapshot 20150821.

[0]
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=46f894d8c60a

* tests/ls/stat-free-color.sh: Change the test to verify that ls(1)
needs the same number of stat-like calls for a single, empty directory
argument as for one with a few directory entries (sub-directory,
regular file, symlink, etc.).

1 files changed, 24 insertions, 15 deletions

diff --git a/tests/ls/stat-free-color.sh b/tests/ls/stat-free-color.sh
index fb2ee8b5a..35816a375 100755
--- a/tests/ls/stat-free-color.sh
+++ b/tests/ls/stat-free-color.sh
@@ -27,8 +27,6 @@ stats='stat,lstat,stat64,lstat64,newfstatat'
 require_strace_ $stats
 require_dirent_d_type_
 
-ln -s nowhere dangle || framework_failure_
-
 # Disable enough features via LS_COLORS so that ls --color
 # can do its job without calling stat (other than the obligatory
 # one-call-per-command-line argument).
@@ -54,22 +52,33 @@ EOF
 eval $(dircolors -b color-without-stat)
 
 # The system may perform additional stat-like calls before main.
-# To avoid counting those, first get a baseline count by running
-# ls with only the --help option.  Then, compare that with the
+# Furthermore, underlying library functions may also implicitly
+# add an extra stat call, e.g. opendir since glibc-2.21-360-g46f894d.
+# To avoid counting those, first get a baseline count for running
+# ls with one empty directory argument.  Then, compare that with the
 # invocation under test.
-strace -o log-help -e $stats ls --help >/dev/null || fail=1
-n_lines_help=$(wc -l < log-help)
+mkdir d || framework_failure_
+
+strace -o log1 -e $stats ls --color=always d || fail=1
+n_stat1=$(wc -l < log1) || framework_failure_
+
+test $n_stat1 = 0 \
+  && skip_ 'No stat calls recognized on this platform'
 
-strace -o log -e $stats ls --color=always . || fail=1
-n_lines=$(wc -l < log)
+# Populate the test directory.
+mkdir d/subdir \
+  && touch d/regf \
+  && ln d/regf d/hlink \
+  && ln -s regf d/slink \
+  && ln -s nowhere d/dangle \
+  || framework_failure_
 
-n_stat=$(expr $n_lines - $n_lines_help)
+# Invocation under test.
+strace -o log2 -e $stats ls --color=always d || fail=1
+n_stat2=$(wc -l < log2) || framework_failure_
 
-# Expect one stat call.
-case $n_stat in
-  0) skip_ 'No stat calls recognized on this platform' ;;
-  1) ;; # Corresponding to stat(".")
-  *) fail=1; head -n30 log* ;;
-esac
+# Expect the same number of stat calls.
+test $n_stat1 = $n_stat2 \
+  || { fail=1; head -n30 log*; }
 
 Exit $fail