Fix bogus list-iteration code in pg_regress.c, affecting ecpg tests only.

While looking at a recent buildfarm failure in the ecpg tests, I wondered
why the pg_regress output claimed the stderr part of the test failed, when
the regression diffs were clearly for the stdout part.  Looking into it,
the reason is that pg_regress.c's logic for iterating over three parallel
lists is wrong, and has been wrong since it was written: it advances the
"tag" pointer at a different place in the loop than the other two pointers.
Fix that.

diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 4b24c4ac71ffca7b13be5ffeeab35877efb27a1c..2ff2acc641b9387ada7c77720f09fdf55ea8a028 100644 (file)
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -1752,14 +1752,11 @@ run_schedule(const char *schedule, test_function tfunc)
             */
            for (rl = resultfiles[i], el = expectfiles[i], tl = tags[i];
                 rl != NULL;    /* rl and el have the same length */
-                rl = rl->next, el = el->next)
+                rl = rl->next, el = el->next,
+                tl = tl ? tl->next : NULL)
            {
                bool        newdiff;
 
-               if (tl)
-                   tl = tl->next;  /* tl has the same length as rl and el if
-                                    * it exists */
-
                newdiff = results_differ(tests[i], rl->str, el->str);
                if (newdiff && tl)
                {
@@ -1848,14 +1845,11 @@ run_single_test(const char *test, test_function tfunc)
     */
    for (rl = resultfiles, el = expectfiles, tl = tags;
         rl != NULL;            /* rl and el have the same length */
-        rl = rl->next, el = el->next)
+        rl = rl->next, el = el->next,
+        tl = tl ? tl->next : NULL)
    {
        bool        newdiff;
 
-       if (tl)
-           tl = tl->next;      /* tl has the same length as rl and el if it
-                                * exists */
-
        newdiff = results_differ(test, rl->str, el->str);
        if (newdiff && tl)
        {