tests: fix test logic for pcre-context

Included in the original bug #20957, but corrupted somehow in
transit as the required NUL characters are missing.

Add a simpler version of the test case that uses plain characters
and match the -z data and output to show the equivalence.

Note the output is still not correct as it is missing the expected
LF characters, but a full fix will have to wait until PCRE2.

Fixes Bug#51735.

1 files changed, 22 insertions, 18 deletions

diff --git a/tests/pcre-context b/tests/pcre-context
index b910a205..77cb8638 100755
--- a/tests/pcre-context
+++ b/tests/pcre-context
@@ -4,29 +4,33 @@
 require_pcre_
 
 cat >in <<'EOF'
-Preceded by 0 empty lines.
-
-Preceded by 1 empty line.
-
-
-Preceded by 2 empty lines.
-
-
-
-Preceded by 3 empty lines.
-
-
-
-
-Preceded by 4 empty lines.
+b0
+ab1
+aab2
+aaab3
+aaaab4
+EOF
+test $? -eq 0 || framework_failure_
 
+cat >exp <<'EOF'
+b3
+ab4
 EOF
 test $? -eq 0 || framework_failure_
 
+grep -Po '(?<=aaa).*' in >out || fail_ 'grep -Po failed'
+compare exp out || fail=1
+
+printf 'NUL preceded by 0 empty lines.\0' >in &&
+printf '\nNUL preceded by 1 empty line.\0' >>in &&
+printf '\n\nNUL preceded by 2 empty lines.\0' >>in &&
+printf '\n\n\nNUL preceded by 3 empty lines.\0' >>in &&
+printf '\n\n\n\nNUL preceded by 4 empty lines.\0' >>in &&
+printf '\n' >>in || framework_failure_
+
 printf '%s\0' \
-       'Preceded by 2 empty lines.' \
-       'Preceded by 3 empty lines.' \
-       'Preceded by 4 empty lines.' >exp || framework_failure_
+       'NUL preceded by 3 empty lines.' \
+       'NUL preceded by 4 empty lines.' >exp || framework_failure_
 
 fail=0