* win32/win32.c (rb_w32_seekdir): should not segfault even if passed

the location which rb_w32_telldir didn't return. (and should change
  `bits' position) [ruby-core:7035]

* win32/dir.h: ditto. (stores `loc' instead of `bitpos')

* test/ruby/test_dir.rb: added.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@9782 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,13 @@
+Sun Jan  1 14:42:54 2006  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
+
+	* win32/win32.c (rb_w32_seekdir): should not segfault even if passed
+	  the location which rb_w32_telldir didn't return. (and should change
+	  `bits' position) [ruby-core:7035]
+
+	* win32/dir.h: ditto. (stores `loc' instead of `bitpos')
+
+	* test/ruby/test_dir.rb: added.
+
 Sat Dec 31 22:57:00 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_thread_save_context): should not recycle scope object used

test/ruby/test_dir.rb

@@ -0,0 +1,42 @@
+require 'test/unit'
+
+require 'tmpdir'
+require 'fileutils'
+
+class TestDir < Test::Unit::TestCase
+
+  ROOT = File.join(Dir.tmpdir, "__test_dir__#{$$}")
+
+  def setup
+    Dir.mkdir(ROOT)
+    for i in ?a..?z
+      if i % 2 == 0
+        FileUtils.touch(File.join(ROOT, i.chr))
+      else
+        FileUtils.mkdir(File.join(ROOT, i.chr))
+      end
+    end
+  end
+
+  def teardown
+    FileUtils.rm_rf ROOT if File.directory?(ROOT)
+  end
+
+  def test_seek
+    dir = Dir.open(ROOT)
+    begin
+      cache = []
+      loop do
+        pos = dir.tell
+        break unless name = dir.read
+        cache << [pos, name]
+      end
+      for x in cache.sort_by {|x| x[0] % 3 } # shuffle
+        dir.seek(x[0])
+        assert_equal(x[1], dir.read)
+      end
+    ensure
+      dir.close
+    end
+  end
+end

win32/dir.h

@@ -21,9 +21,9 @@ typedef struct {
     char *curr;
     long size;
     long nfiles;
+    long loc;  /* [0, nfiles) */
     struct direct dirstr;
     char *bits;  /* used for d_isdir and d_isrep */
-    long bitpos; /* used for d_isdir and d_isrep */
 } DIR;
 
 

win32/win32.c

@@ -1461,6 +1461,21 @@ rb_w32_opendir(const char *filename)
     return p;
 }
 
+//
+// Move to next entry
+//
+
+static void
+move_to_next_entry(DIR *dirp)
+{
+    if (dirp->curr) {
+	dirp->loc++;
+	dirp->curr += strlen(dirp->curr) + 1;
+	if (dirp->curr >= (dirp->start + dirp->size)) {
+	    dirp->curr = NULL;
+	}
+    }
+}
 
 //
 // Readdir just returns the current string pointer and bumps the
@@ -1470,7 +1485,6 @@ rb_w32_opendir(const char *filename)
 struct direct  *
 rb_w32_readdir(DIR *dirp)
 {
-    int         len;
     static int  dummy = 0;
 
     if (dirp->curr) {
@@ -1479,9 +1493,8 @@ rb_w32_readdir(DIR *dirp)
 	// first set up the structure to return
 	//
 
-	len = strlen(dirp->curr);
 	strcpy(dirp->dirstr.d_name, dirp->curr);
-	dirp->dirstr.d_namlen = len;
+	dirp->dirstr.d_namlen = strlen(dirp->curr);
 
 	//
 	// Fake inode
@@ -1491,19 +1504,14 @@ rb_w32_readdir(DIR *dirp)
 	//
 	// Attributes
 	//
-	dirp->dirstr.d_isdir = GetBit(dirp->bits, dirp->bitpos);
+	dirp->dirstr.d_isdir = GetBit(dirp->bits, dirp->loc * 2);
-	dirp->bitpos++;
+	dirp->dirstr.d_isrep = GetBit(dirp->bits, dirp->loc * 2 + 1);
-	dirp->dirstr.d_isrep = GetBit(dirp->bits, dirp->bitpos);
-	dirp->bitpos++;
 
 	//
 	// Now set up for the next call to readdir
 	//
 
-	dirp->curr += len + 1;
+	move_to_next_entry(dirp);
-	if (dirp->curr >= (dirp->start + dirp->size)) {
-	    dirp->curr = NULL;
-	}
 
 	return &(dirp->dirstr);
 
@@ -1518,7 +1526,7 @@ rb_w32_readdir(DIR *dirp)
 long
 rb_w32_telldir(DIR *dirp)
 {
-	return (long) dirp->curr;	/* ouch! pointer to long cast */
+    return dirp->loc;
 }
 
 //
@@ -1528,7 +1536,11 @@ rb_w32_telldir(DIR *dirp)
 void
 rb_w32_seekdir(DIR *dirp, long loc)
 {
-	dirp->curr = (char *) loc;	/* ouch! long to pointer cast */
+    rb_w32_rewinddir(dirp);
+
+    while (dirp->curr && dirp->loc < loc) {
+	move_to_next_entry(dirp);
+    }
 }
 
 //
@@ -1538,8 +1550,8 @@ rb_w32_seekdir(DIR *dirp, long loc)
 void
 rb_w32_rewinddir(DIR *dirp)
 {
-	dirp->curr = dirp->start;
+    dirp->curr = dirp->start;
-	dirp->bitpos = 0;
+    dirp->loc = 0;
 }
 
 //
@@ -1549,9 +1561,9 @@ rb_w32_rewinddir(DIR *dirp)
 void
 rb_w32_closedir(DIR *dirp)
 {
-	free(dirp->start);
+    free(dirp->start);
-	free(dirp->bits);
+    free(dirp->bits);
-	free(dirp);
+    free(dirp);
 }
 
 #if (defined _MT || defined __MSVCRT__) && !defined __BORLANDC__