ruby.c: fix for multiarch library

* ruby.c (ruby_init_loadpath_safe): try two levels upper for stripping
  libdir name.  [Bug #7874]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39348 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,7 @@
-Thu Feb 21 12:42:19 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Thu Feb 21 12:45:03 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ruby.c (ruby_init_loadpath_safe): try two levels upper for stripping
+	  libdir name.  [Bug #7874]
 
 	* configure.in (libdir_basename): expand with multiarch in configure,
 	  not to defer the expansion till ruby.pc.in and mkmf.rb.  [Bug #7874]

configure.in

@@ -2670,6 +2670,9 @@ AS_CASE(["$target_os"],
 AC_ARG_ENABLE(multiarch,
 	      AS_HELP_STRING([--enable-multiarch], [enable multiarch compatible directories]),
 	      [multiarch=], [unset multiarch])
+if test ${multiarch+set}; then
+   AC_DEFINE(ENABLE_MULTIARCH)
+fi
 
 archlibdir='${libdir}/${arch}'
 sitearchlibdir='${libdir}/${sitearch}'

ruby.c

@@ -464,15 +464,30 @@ ruby_init_loadpath_safe(int safe_level)
 #endif
 	const ptrdiff_t bindir_len = (ptrdiff_t)sizeof(bindir) - 1;
 	const ptrdiff_t libdir_len = (ptrdiff_t)sizeof(libdir) - 1;
-	*p = 0;
-	if (p - libpath >= bindir_len && !STRCASECMP(p - bindir_len, bindir)) {
+
+#ifdef ENABLE_MULTIARCH
+	char *p2 = NULL;
+
+      multiarch:
+#endif
+	if (p - libpath >= bindir_len && !STRNCASECMP(p - bindir_len, bindir, bindir_len)) {
 	    p -= bindir_len;
-	    *p = 0;
 	}
-	else if (p - libpath >= libdir_len && !strcmp(p - libdir_len, libdir)) {
+	else if (p - libpath >= libdir_len && !strncmp(p - libdir_len, libdir, libdir_len)) {
 	    p -= libdir_len;
-	    *p = 0;
 	}
+#ifdef ENABLE_MULTIARCH
+	else if (p2) {
+	    p = p2;
+	}
+	else {
+	    p2 = p;
+	    p = rb_enc_path_last_separator(libpath, p, rb_ascii8bit_encoding());
+	    if (p) goto multiarch;
+	    p = p2;
+	}
+#endif
+	*p = 0;
     }
 #if !VARIABLE_LIBPATH
     else {