Perform as-is substitution for %{name} form too, again

- Commit c22d5b1299 changed the parsing
  to require a valid name in %{name} macro, but this outlaws existing
  uses such as %{foo_%{bar}_something}. Relaxing the %{name} form
  to use as-is substitution as well allows these to work again.

rpmio/macro.c

@@ -1106,14 +1106,12 @@ expandMacro(MacroBuf mb, const char *src, size_t slen)
 		}
 		f = parseMacroFlags(s + 1 /* skip { */, &negate, &chkexist);
 		fe = parseMacroName(f);
-		se++;	/* skip } */
-		/* no valid name? syntax error */
+		/* no valid name? assume as-is substitution */
 		if (fe == NULL) {
-			rpmlog(RPMLOG_ERR,
-				_("Invalid macro name: %%%.*s\n"), (int)(se - s), s);
-			rc = 1;
+			mbAppend(mb, '%');
 			continue;
 		}
+		se++;	/* skip } */
 		switch (*fe) {
 		case ':':
 			g = fe + 1;

tests/rpmmacro.at

@@ -33,11 +33,9 @@ runroot rpm --define "this that" --eval '%{?that}'
 ])
 AT_CLEANUP
 
-# XXX this was broken by commit c22d5b12999de6633d89828165ea3ab2112993e8
 AT_SETUP([nested macro in name])
 AT_KEYWORDS([macros])
 AT_CHECK([
-AT_XFAIL_IF([test $RPM_XFAIL -ne 0])
 runroot rpm --define "this that" --define "that_that foo" --eval '%{expand:%{%{this}_that}}'
 ],
 [0],