diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
index 9606c233..78c1be06 100644
--- a/libtiff/tif_dirread.c
+++ b/libtiff/tif_dirread.c
@@ -1,4 +1,4 @@
-/* $Id: tif_dirread.c,v 1.84 2006-04-04 02:00:08 joris Exp $ */
+/* $Id: tif_dirread.c,v 1.85 2006-06-08 14:27:17 dron Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -41,9 +41,11 @@ extern	void TIFFCvtIEEEFloatToNative(TIFF*, uint32, float*);
 extern	void TIFFCvtIEEEDoubleToNative(TIFF*, uint32, double*);
 #endif
 
-static  TIFFDirEntry* TIFFReadDirectoryFind(TIFFDirEntry* dir, uint16 dircount, uint16 tagid);
+static  TIFFDirEntry* TIFFReadDirectoryFind(TIFFDirEntry* dir,
+					    uint16 dircount, uint16 tagid);
 static	int EstimateStripByteCounts(TIFF*, TIFFDirEntry*, uint16);
 static	void MissingRequired(TIFF*, const char*);
+static	int TIFFCheckDirOffset(TIFF*);
 static	int CheckDirCount(TIFF*, TIFFDirEntry*, uint32);
 static	tsize_t TIFFFetchData(TIFF*, TIFFDirEntry*, char*);
 static	tsize_t TIFFFetchString(TIFF*, TIFFDirEntry*, char*);
@@ -82,32 +84,21 @@ TIFFReadDirectory(TIFF* tif)
 	uint16 dircount;
 	toff_t nextdiroff;
 	int diroutoforderwarning = 0;
-	toff_t* new_dirlist;
 
 	tif->tif_diroff = tif->tif_nextdiroff;
 	if (tif->tif_diroff == 0)		/* no more directories */
 		return (0);
 
+	/*
+	 * XXX: Check offset to prevent IFD looping.
+	 */
+	if (!TIFFCheckDirOffset(tif))
+		return 0;
 	/*
 	 * XXX: Trick to prevent IFD looping. The one can create TIFF file
 	 * with looped directory pointers. We will maintain a list of already
 	 * seen directories and check every IFD offset against this list.
 	 */
-	for (n = 0; n < tif->tif_dirnumber; n++) {
-		if (tif->tif_dirlist[n] == tif->tif_diroff)
-			return (0);
-	}
-	tif->tif_dirnumber++;
-	new_dirlist = (toff_t *)_TIFFrealloc(tif->tif_dirlist,
-					tif->tif_dirnumber * sizeof(toff_t));
-	if (!new_dirlist) {
-		TIFFErrorExt(tif->tif_clientdata, module,
-			  "%s: Failed to allocate space for IFD list",
-			  tif->tif_name);
-		return (0);
-	}
-	tif->tif_dirlist = new_dirlist;
-	tif->tif_dirlist[tif->tif_dirnumber - 1] = tif->tif_diroff;
 
 	/*
 	 * Cleanup any previous compression state.
@@ -1048,10 +1039,49 @@ MissingRequired(TIFF* tif, const char* tagname)
 }
 
 /*
- * Check the count field of a directory
- * entry against a known value.  The caller
- * is expected to skip/ignore the tag if
- * there is a mismatch.
+ * Check the directory offset against the list of already seen directory
+ * offsets. This is a trick to prevent IFD looping. The one can create TIFF
+ * file with looped directory pointers. We will maintain a list of already
+ * seen directories and check every IFD offset against that list.
+ */
+static int
+TIFFCheckDirOffset(TIFF* tif)
+{
+	uint16 n;
+
+	for (n = 0; n < tif->tif_dirnumber && tif->tif_dirlist; n++) {
+		if (tif->tif_dirlist[n] == tif->tif_diroff)
+			return 0;
+	}
+
+	tif->tif_dirnumber++;
+
+	if (tif->tif_dirnumber > tif->tif_dirlistsize) {
+		toff_t* new_dirlist;
+
+		/*
+		 * XXX: Reduce memory allocation granularity of the dirlist
+		 * array.
+		 */
+		new_dirlist = (toff_t *)_TIFFCheckRealloc(tif,
+							  tif->tif_dirlist,
+							  tif->tif_dirnumber,
+							  2 * sizeof(toff_t),
+							  "for IFD list");
+		if (!new_dirlist)
+			return 0;
+		tif->tif_dirlistsize = 2 * tif->tif_dirnumber;
+		tif->tif_dirlist = new_dirlist;
+	}
+
+	tif->tif_dirlist[tif->tif_dirnumber - 1] = tif->tif_diroff;
+
+	return 1;
+}
+
+/*
+ * Check the count field of a directory entry against a known value.  The
+ * caller is expected to skip/ignore the tag if there is a mismatch.
  */
 static int
 CheckDirCount(TIFF* tif, TIFFDirEntry* dir, uint32 count)
diff --git a/libtiff/tif_open.c b/libtiff/tif_open.c
index 2a54682a..5fa7aa0d 100644
--- a/libtiff/tif_open.c
+++ b/libtiff/tif_open.c
@@ -1,4 +1,4 @@
-/* $Id: tif_open.c,v 1.32 2006-03-25 03:09:24 joris Exp $ */
+/* $Id: tif_open.c,v 1.33 2006-06-08 14:27:17 dron Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -307,7 +307,8 @@ TIFFClientOpen(
 	if (tif->tif_mode & O_TRUNC ||
 	    !ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
 		if (tif->tif_mode == O_RDONLY) {
-			TIFFErrorExt(tif->tif_clientdata, name, "Cannot read TIFF header");
+			TIFFErrorExt(tif->tif_clientdata, name,
+				     "Cannot read TIFF header");
 			goto bad;
 		}
 		/*
@@ -336,7 +337,8 @@ TIFFClientOpen(
                 TIFFSeekFile( tif, 0, SEEK_SET );
                
 		if (!WriteOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
-			TIFFErrorExt(tif->tif_clientdata, name, "Error writing TIFF header");
+			TIFFErrorExt(tif->tif_clientdata, name,
+				     "Error writing TIFF header");
 			goto bad;
 		}
 		/*
@@ -350,6 +352,7 @@ TIFFClientOpen(
 			goto bad;
 		tif->tif_diroff = 0;
 		tif->tif_dirlist = NULL;
+		tif->tif_dirlistsize = 0;
 		tif->tif_dirnumber = 0;
 		return (tif);
 	}
@@ -366,10 +369,12 @@ TIFFClientOpen(
 	    tif->tif_header.tiff_magic != MDI_LITTLEENDIAN
 #endif
 	    ) {
-		TIFFErrorExt(tif->tif_clientdata, name,  "Not a TIFF or MDI file, bad magic number %d (0x%x)",
+		TIFFErrorExt(tif->tif_clientdata, name,
+			"Not a TIFF or MDI file, bad magic number %d (0x%x)",
 #else
 	    ) {
-		TIFFErrorExt(tif->tif_clientdata, name,  "Not a TIFF file, bad magic number %d (0x%x)",
+		TIFFErrorExt(tif->tif_clientdata, name,
+			     "Not a TIFF file, bad magic number %d (0x%x)",
 #endif
 		    tif->tif_header.tiff_magic,
 		    tif->tif_header.tiff_magic);
diff --git a/libtiff/tiffiop.h b/libtiff/tiffiop.h
index b66fb4e1..3f2df726 100644
--- a/libtiff/tiffiop.h
+++ b/libtiff/tiffiop.h
@@ -1,4 +1,4 @@
-/* $Id: tiffiop.h,v 1.47 2006-03-25 03:09:24 joris Exp $ */
+/* $Id: tiffiop.h,v 1.48 2006-06-08 14:27:17 dron Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -120,6 +120,7 @@ struct tiff {
 	toff_t		tif_nextdiroff;	/* file offset of following directory */
 	toff_t*		tif_dirlist;	/* list of offsets to already seen */
 					/* directories to prevent IFD looping */
+	tsize_t		tif_dirlistsize;/* number of entires in offset list */
 	uint16		tif_dirnumber;  /* number of already seen directories */
 	TIFFDirectory	tif_dir;	/* internal rep of current directory */
 	TIFFHeader	tif_header;	/* file's header block */
@@ -275,6 +276,7 @@ extern	TIFFErrorHandlerExt _TIFFwarningHandlerExt;
 extern	TIFFErrorHandlerExt _TIFFerrorHandlerExt;
 
 extern	tdata_t _TIFFCheckMalloc(TIFF*, size_t, size_t, const char*);
+extern	tdata_t _TIFFCheckRealloc(TIFF*, tdata_t, size_t, size_t, const char*);
 
 extern	int TIFFInitDumpMode(TIFF*, int);
 #ifdef PACKBITS_SUPPORT