diff --git a/ChangeLog b/ChangeLog
index faf156f9..84322a8f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -35,15 +35,19 @@
 - redone im_fwfft(), im_invfft(), im_freqflt(), im_disp_ps(), im_fractsurf(),
   im_phasecor() as classes
 
-20/11/13	started 7.36.5
+9/1/14 started 7.36.6
+- fix some clang compiler warnings
+
+20/11/13 started 7.36.5
 - better cache sizing in unbuffered sequential mode
 - allow larger tile_size in dzsave
 - remove use of PATH_MAX to help gnu hurd
+- fix vips_hist_match()
 
-15/11/13	started 7.36.4
+15/11/13 started 7.36.4
 - improve compat with im_init_world()
 
-18/10/13	started 7.36.3
+18/10/13 started 7.36.3
 - fix compiler warnings in ubuntu 13.10
 - reverse similarity rotation direction to match the convention used 
   elsewhere in vips
diff --git a/libvips/create/buildlut.c b/libvips/create/buildlut.c
index a8a4d56b..da2b1000 100644
--- a/libvips/create/buildlut.c
+++ b/libvips/create/buildlut.c
@@ -14,6 +14,8 @@
  * 	- gtkdoc
  * 2/7/13
  * 	- convert to a class
+ * 10/12/13
+ * 	- be more forgiving about x vales not quite integers
  */
 
 /*
@@ -125,12 +127,16 @@ vips_buildlut_build_init( VipsBuildlut *lut )
 	for( y = 0; y < lut->mat->Ysize; y++ ) {
 		double v = *VIPS_MATRIX( lut->mat, 0, y ); 
 			
-		if( floor( v ) != v ) {
+		/* Allow for being a bit off.
+		 */
+		if( abs( v - VIPS_RINT( v ) ) > 0.001 ) {
 			vips_error( class->nickname,
-				"%s", _( "x value not an int" ) );
+				_( "x value row %d not an int" ), y );
 			return( -1 );
 		}
 
+		v = VIPS_RINT( v ); 
+
 		if( v < xlow )
 			xlow = v;
 		if( v > xhigh )
@@ -189,8 +195,8 @@ vips_buildlut_build_create( VipsBuildlut *lut )
 	 */
 	for( b = 0; b < bands; b++ ) {
 		for( i = 0; i < ysize - 1; i++ ) {
-			const int x1 = lut->data[i][0];
-			const int x2 = lut->data[i + 1][0];
+			const int x1 = VIPS_RINT( lut->data[i][0] );
+			const int x2 = VIPS_RINT( lut->data[i + 1][0] );
 			const int dx = x2 - x1;
 			const double y1 = lut->data[i][b + 1];
 			const double y2 = lut->data[i + 1][b + 1];
diff --git a/libvips/foreign/ppm.c b/libvips/foreign/ppm.c
index 8f49168a..95e0e544 100644
--- a/libvips/foreign/ppm.c
+++ b/libvips/foreign/ppm.c
@@ -512,14 +512,14 @@ vips__ppm_isppm( const char *filename )
 
 /* ppm flags function.
  */
-VipsFormatFlags
+VipsForeignFlags
 vips__ppm_flags( const char *filename )
 {
-	VipsFormatFlags flags;
+	VipsForeignFlags flags;
 
 	flags = 0;
 	if( isppmmmap( filename ) )
-		flags |= VIPS_FORMAT_PARTIAL;
+		flags |= VIPS_FOREIGN_PARTIAL;
 
 	return( flags );
 }
diff --git a/libvips/foreign/ppm.h b/libvips/foreign/ppm.h
index d672f3dd..5bbc5546 100644
--- a/libvips/foreign/ppm.h
+++ b/libvips/foreign/ppm.h
@@ -38,7 +38,7 @@ extern "C" {
 int vips__ppm_header( const char *name, VipsImage *out );
 int vips__ppm_load( const char *name, VipsImage *out );
 int vips__ppm_isppm( const char *filename );
-VipsFormatFlags vips__ppm_flags( const char *filename );
+VipsForeignFlags vips__ppm_flags( const char *filename );
 extern const char *vips__ppm_suffs[];
 
 int vips__ppm_save( VipsImage *in, const char *filename, 
diff --git a/libvips/foreign/radiance.c b/libvips/foreign/radiance.c
index a540f2ef..4275375c 100644
--- a/libvips/foreign/radiance.c
+++ b/libvips/foreign/radiance.c
@@ -1206,7 +1206,6 @@ vips2rad_put_data_block( VipsRegion *region, Rect *area, void *a )
 		VipsPel *p = VIPS_REGION_ADDR( region, 0, area->top + i );
 
 		if( scanline_write( (COLR *) p, area->width, write->fout ) ) 
-		//if( scanline_write_old( (COLR *) p, area->width, write->fout ) ) 
 			return( -1 );
 	}
 
diff --git a/libvips/histogram/hist_match.c b/libvips/histogram/hist_match.c
index d6805da0..8f196385 100644
--- a/libvips/histogram/hist_match.c
+++ b/libvips/histogram/hist_match.c
@@ -14,6 +14,8 @@
  * 	- small cleanups
  * 12/8/13	
  * 	- redone im_histspec() as a class, vips_hist_match()
+ * 19/12/13
+ * 	- oop, upcast input
  */
 
 /*
@@ -138,13 +140,6 @@ vips_hist_match_build( VipsObject *object )
 	return( 0 );
 }
 
-#define UI VIPS_FORMAT_UINT
-
-static const VipsBandFormat vips_hist_match_format_table[10] = {
-/* UC  C   US  S   UI  I   F   X   D   DX */
-   UI, UI, UI, UI, UI, UI, UI, UI, UI, UI 
-};
-
 static void
 vips_hist_match_class_init( VipsHistMatchClass *class )
 {
@@ -159,7 +154,7 @@ vips_hist_match_class_init( VipsHistMatchClass *class )
 	vobject_class->description = _( "match two histograms" );
 	vobject_class->build = vips_hist_match_build;
 
-	hclass->format_table = vips_hist_match_format_table;
+	hclass->input_format = VIPS_FORMAT_UINT; 
 	hclass->process = vips_hist_match_process;
 
 	VIPS_ARG_IMAGE( class, "in", 1, 
diff --git a/libvips/histogram/histogram.c b/libvips/histogram/histogram.c
index 48c1c6b3..e57fe2e5 100644
--- a/libvips/histogram/histogram.c
+++ b/libvips/histogram/histogram.c
@@ -145,11 +145,23 @@ vips_histogram_build( VipsObject *object )
 			vips_check_hist( class->nickname, histogram->in[i] ) )
 			return( -1 ); 
 
-	/* Cast our input images up to a common format, bands and size.
+	/* Cast our input images up to a common format, bands and size. If
+	 * input_format is set, cast to a fixed input type.
 	 */
-	if( vips__formatalike_vec( histogram->in, format, histogram->n ) ||
-		vips__bandalike_vec( class->nickname, 
-			format, band, histogram->n, 1 ) ||
+	if( hclass->input_format != VIPS_FORMAT_NOTSET ) {
+		for( i = 0; i < histogram->n; i++ ) 
+			if( vips_cast( histogram->in[i], &format[i],
+				hclass->input_format, NULL ) )
+				return( -1 ); 
+	}
+	else {
+		if( vips__formatalike_vec( histogram->in, 
+			format, histogram->n ) )
+			return( -1 );
+	}
+		
+	if( vips__bandalike_vec( class->nickname, 
+		format, band, histogram->n, 1 ) ||
 		vips__hist_sizealike_vec( band, size, histogram->n ) ) 
 		return( -1 );
 
@@ -202,6 +214,8 @@ vips_histogram_class_init( VipsHistogramClass *class )
 	vobject_class->description = _( "histogram operations" );
 	vobject_class->build = vips_histogram_build;
 
+	class->input_format = VIPS_FORMAT_NOTSET;
+
 	/* Inputs set by subclassess.
 	 */
 
diff --git a/libvips/histogram/phistogram.h b/libvips/histogram/phistogram.h
index 37d4a518..45ff77a8 100644
--- a/libvips/histogram/phistogram.h
+++ b/libvips/histogram/phistogram.h
@@ -81,6 +81,10 @@ typedef struct _VipsHistogramClass {
 	 */
 	const VipsBandFormat *format_table;
 
+	/* If not VIPS_FORMAT_NOTSET, upcast all ins to this.
+	 */
+	VipsBandFormat input_format;
+
 	VipsHistogramProcessFn process;
 
 } VipsHistogramClass;
diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index 00878f2f..5a59cc86 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -238,7 +238,7 @@ typedef struct _VipsImage {
 	 * guint64 so that we can guarantee to work even on systems with
 	 * strange ideas about large files.
 	 */
-	guint64 sizeof_header;
+	gint64 sizeof_header;
 
 	/* If this is a large disc image, don't map the whole thing, instead
 	 * have a set of windows shared between the regions active on the