TIFFDirectory uses unsigned long which can be 32 or 64 bits

TIFFDirectory’s td_fieldsset[] field is unsigned long which can be 32 or 64 bits.

It should be uint32_t as it is only ever used as a 32-bit unsigned int.

Also, for what it’s worth, TIFFFreeDirectory() only zeros td_fieldsset’s first 4 bytes.

This small patch fixes both of these:

--- tif_dir.orig.h	2022-11-11 21:05:23.000000000 +0000
+++ tif_dir.h	2022-11-11 21:17:27.000000000 +0000
@@ -68,4 +68,2 @@
-#define FIELD_SETLONGS 4
-	/* bit vector of fields that are set */
-	unsigned long td_fieldsset[FIELD_SETLONGS];
-
+#	define FIELDSET_ITEMS	4
+	uint32_t  td_fieldsset[FIELDSET_ITEMS];	/* bit vector of fields that are set */
@@ -194 +192 @@
-#define FIELD_LAST			(32*FIELD_SETLONGS-1)
+#define FIELD_LAST			(32*FIELDSET_ITEMS-1)
@@ -196 +194 @@
-#define BITn(n)				(((unsigned long)1L)<<((n)&0x1f))
+#define BITn(n)				(((uint32_t)1)<<((n)&0x1f))


--- tif_dir.orig.c	2022-11-11 21:05:33.000000000 +0000
+++ tif_dir.c	2022-11-11 21:14:04.000000000 +0000
@@ -1423 +1423 @@
-	_TIFFmemset(td->td_fieldsset, 0, FIELD_SETLONGS);
+	_TIFFmemset(td->td_fieldsset, 0, sizeof(td->td_fieldsset));