From a230979d98fdf45421a7d85e7201f5069bb6c108 Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Mon, 27 Feb 2006 08:38:57 +0000
Subject: [PATCH] * (bug 5062) Width sometimes one pixel short when using
 maximum heights

---
 RELEASE-NOTES       |  1 +
 includes/Image.php  | 23 +++++++++++++---
 tests/ImageTest.php | 66 +++++++++++++++++++++++++++++++++++++++++++++
 tests/RunTests.php  |  9 ++++++-
 4 files changed, 94 insertions(+), 5 deletions(-)
 create mode 100644 tests/ImageTest.php

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 87f2b8880d..f1c2f6305c 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -666,6 +666,7 @@ fully support the editing toolbar, but was found to be too confusing.
 * (bug 5086) Force image resize dimensions on ImageMagick, as for instance
   "-resize 100x35!"; some thumbs were off due to differences in rounding and
   would be generated smaller than expected.
+* (bug 5062) Width sometimes one pixel short when using maximum heights
 
 
 === Caveats ===
diff --git a/includes/Image.php b/includes/Image.php
index 309a1d7dcf..0afad6817f 100644
--- a/includes/Image.php
+++ b/includes/Image.php
@@ -867,10 +867,7 @@ class Image
 
 		if ($this->canRender()) {
 			if ( $width > $this->width * $height / $this->height )
-				$width = floor( $this->width * $height / $this->height );
-				# Note this is the largest width such that the thumbnail's
-				# height is at most $height.
-
+				$width = wfFitBoxWidth( $this->width, $this->height, $height );
 			$thumb = $this->renderThumb( $width );
 		}
 		else $thumb= NULL; #not a bitmap or renderable image, don't try.
@@ -1919,4 +1916,22 @@ class ThumbnailImage {
 	}
 
 }
+
+/**
+ * Calculate the largest thumbnail width for a given original file size
+ * such that the thumbnail's height is at most $maxHeight.
+ * @param int $boxWidth
+ * @param int $boxHeight
+ * @param int $maxHeight
+ * @return int
+ */
+function wfFitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) {
+	$idealWidth = $boxWidth * $maxHeight / $boxHeight;
+	$roundedUp = ceil( $idealWidth );
+	if( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight )
+		return floor( $idealWidth );
+	else
+		return $roundedUp;
+}
+
 ?>
diff --git a/tests/ImageTest.php b/tests/ImageTest.php
new file mode 100644
index 0000000000..b06d4cbf90
--- /dev/null
+++ b/tests/ImageTest.php
@@ -0,0 +1,66 @@
+<?php
+
+require_once( 'PHPUnit.php' );
+require_once( '../includes/Defines.php' );
+require_once( '../includes/Profiling.php' );
+require_once( '../includes/GlobalFunctions.php' );
+require_once( '../includes/Image.php' );
+
+class ImageTest extends PHPUnit_TestCase {
+	function ImageTest( $name ) {
+		$this->PHPUnit_TestCase( $name );
+	}
+
+	function setUp() {
+	}
+
+	function tearDown() {
+	}
+	
+	function testFitBoxWidth() {
+		$vals = array(
+			array(
+				'width' => 50,
+				'height' => 50,
+				'tests' => array(
+					50 => 50,
+					17 => 17,
+					18 => 18 ) ),
+			array(
+				'width' => 366,
+				'height' => 300,
+				'tests' => array(
+					50 => 61,
+					17 => 21,
+					18 => 22 ) ),
+			array(
+				'width' => 300,
+				'height' => 366,
+				'tests' => array(
+					50 => 41,
+					17 => 14,
+					18 => 15 ) ),
+			array(
+				'width' => 100,
+				'height' => 400,
+				'tests' => array(
+					50 => 12,
+					17 => 4,
+					18 => 4 ) ) );
+		foreach( $vals as $row ) {
+			extract( $row );
+			foreach( $tests as $max => $expected ) {
+				$y = round( $expected * $height / $width );
+				$result = wfFitBoxWidth( $width, $height, $max );
+				$y2 = round( $result * $height / $width );
+				$this->assertEquals( $expected,
+					$result,
+					"($width, $height, $max) wanted: {$expected}x$y, got: {$result}x$y2" );
+			}
+		}
+	}
+
+	/* TODO: many more! */
+}
+
+?>
\ No newline at end of file
diff --git a/tests/RunTests.php b/tests/RunTests.php
index 4e6e64160d..e3486ef5b5 100644
--- a/tests/RunTests.php
+++ b/tests/RunTests.php
@@ -35,8 +35,15 @@ $tests = array(
 	'SearchMySQL4Test',
 	'ArticleTest',
 	'SanitizerTest',
-	'CtypeTest'
+	'CtypeTest',
+	'ImageTest'
 	);
+
+if( isset( $_SERVER['argv'][1] ) ) {
+	// to override...
+	$tests = array( $_SERVER['argv'][1] );
+}
+
 foreach( $tests as $test ) {
 	require_once( $test . '.php' );
 	$suite = new PHPUnit_TestSuite( $test );
-- 
2.20.1