From 7025fe408131dc40b84999493fc98a123c4a5eb8 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 16 Nov 2012 19:53:59 +0000
Subject: [PATCH] more exif read improvements

some jpegs use a signed long to store the resolution unit (??), remove
the checks on tag format for res unit
---
 libvips/foreign/jpeg2vips.c |  5 ++---
 libvips/foreign/vips2jpeg.c | 12 +++++-------
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/libvips/foreign/jpeg2vips.c b/libvips/foreign/jpeg2vips.c
index 50f1dc52..cfc9f87f 100644
--- a/libvips/foreign/jpeg2vips.c
+++ b/libvips/foreign/jpeg2vips.c
@@ -484,12 +484,11 @@ get_entry_double( ExifData *ed, int ifd, ExifTag tag, double *out )
 }
 
 static int
-get_entry_short( ExifData *ed, int ifd, ExifTag tag, int *out )
+get_entry_int( ExifData *ed, int ifd, ExifTag tag, int *out )
 {
 	ExifEntry *entry;
 
 	if( !(entry = exif_content_get_entry( ed->ifd[ifd], tag )) ||
-		entry->format != EXIF_FORMAT_SHORT ||
 		entry->components != 1 )
 		return( -1 );
 
@@ -507,7 +506,7 @@ set_vips_resolution( VipsImage *im, ExifData *ed )
 	 */
 	if( get_entry_double( ed, 0, EXIF_TAG_X_RESOLUTION, &xres ) ||
 		get_entry_double( ed, 0, EXIF_TAG_Y_RESOLUTION, &yres ) ||
-		get_entry_short( ed, 0, EXIF_TAG_RESOLUTION_UNIT, &unit ) ) {
+		get_entry_int( ed, 0, EXIF_TAG_RESOLUTION_UNIT, &unit ) ) {
 		vips_warn( "VipsJpeg", 
 			"%s", _( "error reading resolution" ) );
 		return;
diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index c7438793..4f173499 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -417,14 +417,12 @@ typedef void (*write_fn)( ExifData *ed,
 /* Write a tag. Update what's there, or make a new one.
  */
 static int
-write_tag( ExifData *ed, int ifd, 
-	ExifTag tag, ExifFormat format, write_fn fn, void *data )
+write_tag( ExifData *ed, int ifd, ExifTag tag, write_fn fn, void *data )
 {
 	ExifEntry *entry;
 
 	if( (entry = exif_content_get_entry( ed->ifd[ifd], tag )) ) {
-		if( entry->format == format ) 
-			fn( ed, entry, 0, data );
+		fn( ed, entry, 0, data );
 	}
 	else {
 		entry = exif_entry_new();
@@ -484,11 +482,11 @@ set_exif_resolution( ExifData *ed, VipsImage *im )
 	/* Main image xres/yres/unit are in ifd0. ifd1 has the thumbnail
 	 * xres/yres/unit.
 	 */
-	if( write_tag( ed, 0, EXIF_TAG_X_RESOLUTION, EXIF_FORMAT_RATIONAL, 
+	if( write_tag( ed, 0, EXIF_TAG_X_RESOLUTION, 
 		vips_exif_set_double, (void *) &xres ) ||
-		write_tag( ed, 0, EXIF_TAG_Y_RESOLUTION, EXIF_FORMAT_RATIONAL, 
+		write_tag( ed, 0, EXIF_TAG_Y_RESOLUTION, 
 			vips_exif_set_double, (void *) &yres ) ||
-		write_tag( ed, 0, EXIF_TAG_RESOLUTION_UNIT, EXIF_FORMAT_SHORT, 
+		write_tag( ed, 0, EXIF_TAG_RESOLUTION_UNIT, 
 			vips_exif_set_int, (void *) &unit ) ) {
 		vips_error( "VipsJpeg", 
 			"%s", _( "error setting JPEG resolution" ) );