Backport of Bug#53303 mytap tests should always have a plan()

The bug was caused by buffered output. Flushing resolved it.
We still recommend to allways call plan().
  
Also fix some compile warnings (formal parameter different from declaration)

unittest/examples/Makefile.am

@@ -20,7 +20,8 @@ AM_LDFLAGS         = -L$(top_builddir)/unittest/mytap
 
 LDADD              = -lmytap
 
-noinst_PROGRAMS    = simple-t skip-t todo-t skip_all-t no_plan-t core-t
+# We omit core-t here, since it will always fail.
+noinst_PROGRAMS    = simple-t skip-t todo-t skip_all-t no_plan-t
 
 # Don't update the files from bitkeeper
 %::SCCS/s.%

unittest/examples/no_plan-t.c

-/* Copyright (C) 2006 MySQL AB
+/* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. 
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -20,14 +20,19 @@
 
 /*
   Sometimes, the number of tests is not known beforehand. In those
-  cases, the plan can be omitted and will instead be written at the
-  end of the test (inside exit_status()).
+  cases, you should invoke plan(NO_PLAN).
+  The plan will be printed at the end of the test (inside exit_status()).
 
   Use this sparingly, it is a last resort: planning how many tests you
   are going to run will help you catch that offending case when some
   tests are skipped for an unknown reason.
 */
 int main() {
+  /*
+    We recommend calling plan(NO_PLAN), but want to verify that
+    omitting the call works as well.
+    plan(NO_PLAN);
+  */
   ok(1, " ");
   ok(1, " ");
   ok(1, " ");

unittest/mytap/tap.c

-/* Copyright (C) 2006 MySQL AB
+/* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. 
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -40,7 +40,7 @@
 
    @ingroup MyTAP_Internal
  */
-static TEST_DATA g_test = { 0, 0, 0, "" };
+static TEST_DATA g_test = { NO_PLAN, 0, 0, "" };
 
 /**
    Output stream for test report message.
@@ -74,6 +74,7 @@ vemit_tap(int pass, char const *fmt, va_list ap)
           (fmt && *fmt) ? " - " : "");
   if (fmt && *fmt)
     vfprintf(tapout, fmt, ap);
+  fflush(tapout);
 }
 
 
@@ -96,6 +97,7 @@ static void
 emit_dir(const char *dir, const char *why)
 {
   fprintf(tapout, " # %s %s", dir, why);
+  fflush(tapout);
 }
 
 
@@ -108,6 +110,7 @@ static void
 emit_endl()
 {
   fprintf(tapout, "\n");
+  fflush(tapout);
 }
 
 static void
@@ -183,7 +186,10 @@ plan(int const count)
     break;
   default:
     if (count > 0)
+    {
       fprintf(tapout, "1..%d\n", count);
+      fflush(tapout);
+    }
     break;
   }
 }
@@ -196,6 +202,7 @@ skip_all(char const *reason, ...)
   va_start(ap, reason);
   fprintf(tapout, "1..0 # skip ");
   vfprintf(tapout, reason, ap);
+  fflush(tapout);
   va_end(ap);
   exit(0);
 }
@@ -218,7 +225,7 @@ ok(int const pass, char const *fmt, ...)
 
 
 void
-skip(int how_many, char const *const fmt, ...)
+skip(int how_many, char const *fmt, ...)
 {
   char reason[80];
   if (fmt && *fmt)

unittest/mytap/tap.h

-/* Copyright (C) 2006 MySQL AB
+/* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. 
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -72,10 +72,9 @@ extern "C" {
 /**
    Set number of tests that is planned to execute.
 
-   The function also accepts the predefined constant
-   <code>NO_PLAN</code>.  If the function is not called, it is as if
-   it was called with <code>NO_PLAN</code>, i.e., the test plan will
-   be printed after all the test lines.
+   The function also accepts the predefined constant <code>NO_PLAN</code>.
+   If invoked with this constant -- or not invoked at all --
+   the test plan will be printed after all the test lines.
 
    The plan() function will install signal handlers for all signals
    that generate a core, so if you want to override these signals, do
@@ -84,7 +83,7 @@ extern "C" {
    @param count The planned number of tests to run. 
 */
 
-void plan(int count);
+void plan(int const count);
 
 
 /**
@@ -103,7 +102,7 @@ void plan(int count);
                which case nothing is printed.
 */
 
-void ok(int pass, char const *fmt, ...)
+void ok(int const pass, char const *fmt, ...)
   __attribute__((format(printf,2,3)));