From 3673808aa44203db7d1378371637741ec952ce26 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 22 Jan 2010 16:56:57 +0000
Subject: [PATCH] flood fixes

---
 ChangeLog               |  1 +
 TODO                    |  8 ++++++++
 libvips/inplace/flood.c | 12 ++++++++++++
 libvips/iofuncs/check.c |  7 +++++--
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a0ee3a7b..637f9af4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,6 +21,7 @@
 - added "written" callbacks, used to implement write to non-vips formats
 - "invalidate" is careful to keep images alive, so invalidate callbacks can do
   im_close()
+- flood_blob could loop if start point == ink
 
 26/11/09 started 7.20.3
 - updated en_GB.po translation 
diff --git a/TODO b/TODO
index bedff8b3..ad793dec 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,14 @@
 - how about im_invalidate_area()? we currently repaint the whole window on
   every paint action in nip2 :-(
 
+  we'd need to have coordinate transforms broken out for this :-( 
+
+- should im_rwcheck() copy to disc?
+
+  maybe im_rwcheck_disc() copies to im->filename and maps that
+
+  rather awfward to do atm
+
 - flood blob with ink == initial click loops
 
 - we sill have the old flood-fill code there, move to deprecated
diff --git a/libvips/inplace/flood.c b/libvips/inplace/flood.c
index 205ed324..d9ced19c 100644
--- a/libvips/inplace/flood.c
+++ b/libvips/inplace/flood.c
@@ -21,6 +21,8 @@
  * 21/12/09
  * 	- rewrite for a scanline based fill, about 4x faster!
  * 	- allow separate test and mark images
+ * 22/1/10
+ * 	- flood_blob could loop if start point == ink
  */
 
 /*
@@ -501,6 +503,7 @@ int
 im_flood_blob( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
 {
 	Flood *flood;
+ 	int j;
 
 	if( im_rwcheck( im ) ||
 		im_check_known_coded( "im_flood", im ) )
@@ -513,6 +516,15 @@ im_flood_blob( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
 	memcpy( flood->edge, IM_IMAGE_ADDR( im, x, y ), flood->tsize );
 	flood->equal = 1;
 
+	/* If edge == ink, we'll never stop :-( or rather, there's nothing to
+	 * do.
+	 */
+	for( j = 0; j < flood->tsize; j++ ) 
+		if( flood->edge[j] != flood->ink[j] ) 
+			break;
+	if( j == flood->tsize )
+		return( 0 );
+
 	flood_all( flood, x, y );
 
 	flood_free( flood );
diff --git a/libvips/iofuncs/check.c b/libvips/iofuncs/check.c
index acf7ef9b..4e0b8ad8 100644
--- a/libvips/iofuncs/check.c
+++ b/libvips/iofuncs/check.c
@@ -225,12 +225,15 @@ im_incheck( IMAGE *im )
 		break;
 
 	case IM_OPENOUT:
-		/* Close file down and reopen as input.
+		/* Close file down and reopen as input. I guess this will only
+		 * work for vips files?
 		 */
 #ifdef DEBUG_IO
 		printf( "im_incheck: auto-rewind of %s\n", im->filename );
 #endif/*DEBUG_IO*/
-		if( im__close( im ) || im_openin( im ) ) {
+		if( im__close( im ) || 
+			im_openin( im ) ||
+			im_incheck( im ) ) {
 			im_error( "im_incheck", 
 				_( "auto-rewind for %s failed" ),
 				im->filename );