[FYI] {master} tests: TAP-based tests should error if no plan was specified

[Stefano Lattarini]

After this change, it will still be OK for TAP-based tests not to
report any explicit TAP plan -- but they should state *explicitly*
that they want to do so, by calling the 'plan_' function with a
proper argument (currently, either "later" or "unknonwn").

Motivated by a recent issue introduced by yesterday's commit
'v1.11-1959-g0699a84' (pointed out by Peter Rosin, and fixed
by follow-up commit 'v1.11-1961-gea44190').

* tests/tap-functions.sh (plan_): Get rid of '$have_tap_plan_',
and refactor use and initialization of '$planned_' in a way that
will allow client script to get more information on which kind
of plan (if any) has been declared by the former 'plan_' invocation.
(skip_all_): Adjust.
* tests/defs (exit trap): Only print the "lazy" TAP plan if 'plan_'
has requested that *explicitly*.
* syntax-check.mk (sc_tests_tap_plan): Remove: it's obsolete now,
since a TAP-based test that doesn't call 'plan_' explicitly won't
print any TAP plan, and the TAP driver will catch that and report
an error.
(syntax_check_rules): Adjust.
---
 syntax-checks.mk       |   28 ----------------------------
 tests/defs             |    2 +-
 tests/tap-functions.sh |   17 ++++++++++-------
 3 files changed, 11 insertions(+), 36 deletions(-)

diff --git a/syntax-checks.mk b/syntax-checks.mk
index 13531bd..a8bdcad 100644
--- a/syntax-checks.mk
+++ b/syntax-checks.mk
@@ -68,7 +68,6 @@ sc_tests_automake_fails \
 sc_tests_plain_aclocal \
 sc_tests_plain_perl \
 sc_tests_required_after_defs \
-sc_tests_tap_plan \
 sc_tests_overriding_macros_on_cmdline \
 sc_tests_plain_sleep \
 sc_tests_plain_egrep_fgrep \
@@ -426,33 +425,6 @@ sc_tests_required_after_defs:
          fi; \
        done
 
-## TAP-based test scripts should not forget to declare a TAP plan.  In
-## case it is not known in advance how many tests will be run, a "lazy"
-## plan can be used; but its use should be deliberate, explicitly declared
-## with a "plan_ later" call, rather than the result of an oversight.
-## This check helps to ensure this is indeed the case.
-sc_tests_tap_plan:
-       @with_plan=`grep -l '^ *plan_ ' $(srcdir)/tests/*.tap`; \
-        with_plan=`echo $$with_plan`; \
-        ok=:; \
-        for t in $(srcdir)/tests/*.tap; do \
-          case " $$with_plan " in *" $$t "*) continue;; esac; \
-          case $$t in \
-            *-w.tap) \
-              : it is ok for an *auto-generated* test sourcing an \
-              : hand-written one not to declare a TAP plan: that will \
-              : be done by the sourced test; \
-              t2=`echo $$t | sed -e 's|.*/||' -e 's/-w\.tap$$/.tap/'` \
-                && grep -E "^ *\\.  *[^        ]*/$$t2\\b" $$t >/dev/null \
-                && continue || : ;; \
-          esac; \
-          ok=false; echo $$t; \
-        done; \
-        $$ok || { \
-         echo 'The tests above do not declare a TAP plan.' 1>&2; \
-         exit 1; \
-        }
-
 ## Overriding a Makefile macro on the command line is not portable when
 ## recursive targets are used.  Better use an envvar.  SHELL is an
 ## exception, POSIX says it can't come from the environment.  V, DESTDIR,
diff --git a/tests/defs b/tests/defs
index 7af8f25..505a43f 100644
--- a/tests/defs
+++ b/tests/defs
@@ -1053,7 +1053,7 @@ if test "$sh_errexit_works" = yes; then
     set +e
     cd "$testbuilddir"
     if test $am_using_tap = yes; then
-      if test $have_tap_plan_ != yes && test $exit_status -eq 0; then
+      if test "$planned_" = later && test $exit_status -eq 0; then
         plan_ "now"
       fi
       test $exit_status -eq 0 && test $tap_pass_count_ -eq $tap_count_ \
diff --git a/tests/tap-functions.sh b/tests/tap-functions.sh
index 50abc70..700904b 100644
--- a/tests/tap-functions.sh
+++ b/tests/tap-functions.sh
@@ -64,19 +64,22 @@ plan_ ()
     bailout_ "plan_: missing argument"
   elif test $# -ge 2; then
     bailout_ "plan_: too many arguments"
+  elif test x"$planned_" != x"none" && test x"$planned_" != x"later"; then
+    bailout_ "plan_: called to many times"
   elif test x"$1" = x"unknown" || test x"$1" = x"later"; then
-    : No-op.
+    # This means we want to get back later to declaring the TAP plan.
+    planned_=later
+    return 0
   elif test x"$1" = x"lazy" || test x"$1" = x"now"; then
-    echo "1..$tap_count_" # Number of test results seen so far.
-    have_tap_plan_=yes
+    planned_=$tap_count_ # Number of test results seen so far.
   elif test $1 -ge 0; then
-    echo "1..$1"
-    have_tap_plan_=yes
+    planned_=$1
   else
     bailout_ "plan_: invalid argument '$1'"
   fi
+  echo "1..$planned_"
 }
-have_tap_plan_=no # Avoid interferences from the environment.
+planned_=none
 
 # diag_ [EXPLANATION]
 # ------------------
@@ -176,7 +179,7 @@ skip_row_ ()
 skip_all_ ()
 {
   echo "1..0 # SKIP" ${1+"$@"}
-  have_tap_plan_=yes
+  planned_=0
   Exit 0
 }
 
-- 
1.7.9