Revert "Revert "postpone perl_parse() exit(0) bugfix""

This reverts commit 2773b4f.

I haven't made much progress in resolving the problems this produces
downstream, so rather than leaving it broken, I'll revert it until
they can be solved.

perl.c

@@ -1624,13 +1624,16 @@ For historical reasons, the non-zero return value also attempts to
 be a suitable value to pass to the C library function C<exit> (or to
 return from C<main>), to serve as an exit code indicating the nature
 of the way initialisation terminated.  However, this isn't portable,
-due to differing exit code conventions.  An attempt is made to return
-an exit code of the type required by the host operating system, but
-because it is constrained to be non-zero, it is not necessarily possible
-to indicate every type of exit.  It is only reliable on Unix, where a
-zero exit code can be augmented with a set bit that will be ignored.
-In any case, this function is not the correct place to acquire an exit
-code: one should get that from L</perl_destruct>.
+due to differing exit code conventions.  A historical bug is preserved
+for the time being: if the Perl built-in C<exit> is called during this
+function's execution, with a type of exit entailing a zero exit code
+under the host operating system's conventions, then this function
+returns zero rather than a non-zero value.  This bug, [perl #2754],
+leads to C<perl_run> being called (and therefore C<INIT> blocks and the
+main program running) despite a call to C<exit>.  It has been preserved
+because a popular module-installing module has come to rely on it and
+needs time to be fixed.  This issue is [perl #132577], and the original
+bug is due to be fixed in Perl 5.30.
 
 =cut
 */
@@ -1839,7 +1842,15 @@ perl_parse(pTHXx_ XSINIT_t xsinit, int argc, char **argv, char **env)
 	    call_list(oldscope, PL_checkav);
 	}
 	ret = STATUS_EXIT;
-	if (ret == 0) ret = 0x100;
+	if (ret == 0) {
+	    /*
+	     * At this point we should do
+	     *     ret = 0x100;
+	     * to avoid [perl #2754], but that bugfix has been postponed
+	     * because of the Module::Install breakage it causes
+	     * [perl #132577].
+	     */
+	}
 	break;
     case 3:
 	PerlIO_printf(Perl_error_log, "panic: top_env\n");

t/op/blocks.t

@@ -167,23 +167,23 @@ SKIP: {
     skip "VMS doesn't have the perl #2754 bug", 3 if $^O eq 'VMS';
     fresh_perl_is(
         "$testblocks BEGIN { exit 0; }",
-        "begin\nunitcheck\ncheck\nend",
+        "begin\nunitcheck\ncheck\ninit\nend",
         {},
-        "BEGIN{exit 0} should exit"
+        "BEGIN{exit 0} doesn't exit yet"
     );
 
     fresh_perl_is(
         "$testblocks UNITCHECK { exit 0; }",
-        "begin\nunitcheck\ncheck\nend",
+        "begin\nunitcheck\ncheck\ninit\nmain\nend",
         {},
-        "UNITCHECK{exit 0} should exit"
+        "UNITCHECK{exit 0} doesn't exit yet"
     );
 
     fresh_perl_is(
         "$testblocks CHECK { exit 0; }",
-        "begin\nunitcheck\ncheck\nend",
+        "begin\nunitcheck\ncheck\ninit\nmain\nend",
         {},
-        "CHECK{exit 0} should exit"
+        "CHECK{exit 0} doesn't exit yet"
     );
 }