file.c: home dir fall back

* file.c (rb_home_dir_of): return the default home path if the
  user name is the current user name, on platforms where struct
  pwd is not supported.  a temporary measure against
  [Bug #12226].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54947 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Sun May  8 18:51:33 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* file.c (rb_home_dir_of): return the default home path if the
+	  user name is the current user name, on platforms where struct
+	  pwd is not supported.  a temporary measure against
+	  [Bug #12226].
+
 Sun May  8 08:51:38 2016  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* configure.in: add -Wsuggest-attribute=format and suppress warnings.

file.c

@@ -3178,17 +3178,25 @@ copy_home_path(VALUE result, const char *dir)
 VALUE
 rb_home_dir_of(VALUE user, VALUE result)
 {
+    const char *dir, *username = RSTRING_PTR(user);
 #ifdef HAVE_PWD_H
-    struct passwd *pwPtr = getpwnam(RSTRING_PTR(user));
+    struct passwd *pwPtr = getpwnam(username);
+#else
+    extern char *getlogin(void);
+    const char *pwPtr = 0;
+    # define endpwent() ((void)0)
+    if (strcasecmp(username, getlogin()) == 0)
+	dir = pwPtr = getenv("HOME");
+#endif
     if (!pwPtr) {
 	endpwent();
-#endif
 	rb_raise(rb_eArgError, "user %"PRIsVALUE" doesn't exist", user);
-#ifdef HAVE_PWD_H
     }
-    copy_home_path(result, pwPtr->pw_dir);
-    endpwent();
+#ifdef HAVE_PWD_H
+    dir = pwPtr->pw_dir;
 #endif
+    copy_home_path(result, dir);
+    endpwent();
     return result;
 }
 

test/ruby/test_dir.rb

@@ -295,6 +295,10 @@ def test_home
     assert_nothing_raised(ArgumentError) {
       assert_equal(@nodir, Dir.home)
       assert_equal(@nodir, Dir.home(""))
+      if user = ENV["USER"]
+        ENV["HOME"] = env_home
+        assert_equal(File.expand_path(env_home), Dir.home(user))
+      end
     }
     %W[no:such:user \u{7559 5b88}:\u{756a}].each do |user|
       assert_raise_with_message(ArgumentError, /#{user}/) {Dir.home(user)}