fix a few small things

found with clang static analyzer

README.md

@@ -112,7 +112,7 @@ Clang build:
 
 Clang static analysis:
 
-	$ scan-build ./configure --disable-introspection
+	$ scan-build ./configure --disable-introspection --disable-debug
 	$ scan-build -o scan -v make 
 	$ scan-view scan/2013-11-22-2
 

libvips/colour/LCh2Lab.c

@@ -102,6 +102,11 @@ vips_col_Ch2ab( float C, float h, float *a, float *b )
 	float out[3];
 	float *x;
 
+	/* could be anything, we don't use this value, but we must supply one
+	 * or static analyzers will complain.
+	 */
+	in[0] = 50.0;
+
 	in[1] = C;
 	in[2] = h;
 	x = &in[0];

libvips/conversion/smartcrop.c

@@ -286,6 +286,8 @@ vips_smartcrop_build( VipsObject *object )
 
 	switch( smartcrop->interesting ) {
 	case VIPS_INTERESTING_NONE:
+		left = 0;
+		top = 0;
 		break;
 
 	case VIPS_INTERESTING_CENTRE:

libvips/convolution/convi.c

@@ -932,6 +932,10 @@ vips_convi_build( VipsObject *object )
 		return( -1 );
 	in = t[0]; 
 
+	/* Default to the C path.
+	 */
+	generate = vips_convi_gen;
+
 	/* For uchar input, try to make a vector path.
 	 */
 	if( vips_vector_isenabled() &&
@@ -946,9 +950,11 @@ vips_convi_build( VipsObject *object )
 			vips_convi_compile_free( convi );
 	}
 
-	/* If there's no vector path, fall back to C.
+	/* Make the data for the C path.
 	 */
-	if( !convi->n_pass ) {
+	if( generate == vips_convi_gen ) { 
+		g_info( "using C path" ); 
+
 		/* Make an int version of our mask.
 		 */
 		if( vips__image_intize( M, &t[1] ) )
@@ -977,9 +983,6 @@ vips_convi_build( VipsObject *object )
 			convi->coeff_pos[0] = 0;
 			convi->nnz = 1;
 		}
-
-		generate = vips_convi_gen;
-		g_info( "using C path" ); 
 	}
 
 	g_object_set( convi, "out", vips_image_new(), NULL ); 

libvips/convolution/convsep.c

@@ -76,7 +76,7 @@ vips_convsep_build( VipsObject *object )
 	in = convolution->in;
 
 	if( convsep->precision == VIPS_PRECISION_APPROXIMATE ) {
-		if( vips_convasep( convolution->in, &t[0], convolution->M,
+		if( vips_convasep( in, &t[0], convolution->M,
 			"layers", convsep->layers,
 			NULL ) )
 			return( -1 ); 
@@ -90,7 +90,7 @@ vips_convsep_build( VipsObject *object )
 		 */
 		vips_image_set_double( t[0], "offset", 0 );
 
-		if( vips_conv( convolution->in, &t[1], convolution->M, 
+		if( vips_conv( in, &t[1], convolution->M, 
 				"precision", convsep->precision,
 				"layers", convsep->layers,
 				"cluster", convsep->cluster,

libvips/foreign/tiff2vips.c

@@ -1462,6 +1462,11 @@ rtiff_fill_region( VipsRegion *out, void *seq, void *a, void *b, gboolean *stop
 	while( y < r->height ) {
 		VipsRect tile, page, hit;
 
+		/* Not necessary, but it stops static analyzers complaining
+		 * about a used-before-set.
+		 */
+		tile.height = 0;
+
 		x = 0;
 		while( x < r->width ) { 
 			int page_no = rtiff->page + (r->top + y) / 

libvips/iofuncs/buffer.c

@@ -507,6 +507,7 @@ vips_buffer_new( VipsImage *im, VipsRect *area )
 		g_assert( buffer->cache );
 
 		buffer->ref_count = 1;
+		buffer->done = FALSE;
 		buffer->cache = NULL;
 	}
 	else {