From d0e6a4c0f35649e7b940ec4fe7c46c9faa9c761c Mon Sep 17 00:00:00 2001
From: Lovell Fuller <github@lovell.info>
Date: Tue, 4 Mar 2014 22:44:53 +0000
Subject: [PATCH] Support identity transform when both width and height are not
 specified

---
 index.js      |  4 ----
 src/sharp.cc  |  7 ++++---
 tests/unit.js | 58 ++++++++++++++++++++++++++++++++++-----------------
 3 files changed, 43 insertions(+), 26 deletions(-)

diff --git a/index.js b/index.js
index fa8ab09d..55ed7f48 100755
--- a/index.js
+++ b/index.js
@@ -42,10 +42,6 @@ module.exports.resize = function(input, output, width, height, options, callback
     callback("Invalid height " + height);
     return;
   }
-  if (outWidth < 1 && outHeight < 1) {
-    callback("Width and/or height required");
-    return;
-  }
   var canvas = options.canvas || "c";
   if (canvas.length !== 1 || "cwb".indexOf(canvas) === -1) {
     callback("Invalid canvas " + canvas);
diff --git a/src/sharp.cc b/src/sharp.cc
index 67110015..74b8f52e 100755
--- a/src/sharp.cc
+++ b/src/sharp.cc
@@ -132,9 +132,10 @@ void resize_async(uv_work_t *work) {
     factor = yfactor;
     baton->width = floor(in->Xsize * factor);
   } else {
-    resize_error(baton, in);
-    (baton->err).append("Width and/or height required");
-    return;
+    // Identity transform
+    factor = 1;
+    baton->width = in->Xsize;
+    baton->height = in->Ysize;
   }
 
   factor = std::max(factor, 1.0);
diff --git a/tests/unit.js b/tests/unit.js
index 3a9b82e9..aef95a43 100755
--- a/tests/unit.js
+++ b/tests/unit.js
@@ -1,34 +1,54 @@
 var sharp = require("../index");
 var imagemagick = require("imagemagick");
 var assert = require("assert");
+var async = require("async");
 
 var inputJpg = __dirname + "/2569067123_aca715a2ee_o.jpg"; // http://www.flickr.com/photos/grizdave/2569067123/
 var outputJpg = __dirname + "/output.jpg";
 
-sharp.resize(inputJpg, outputJpg, 320, 240, function(err) {
-  if (err) throw err;
-  imagemagick.identify(outputJpg, function(err, features) {
-    if (err) throw err;
-    assert.strictEqual(320, features.width);
-    assert.strictEqual(240, features.height);
-
+async.series([
+  function(done) {
+    sharp.resize(inputJpg, outputJpg, 320, 240, function(err) {
+      if (err) throw err;
+      imagemagick.identify(outputJpg, function(err, features) {
+        if (err) throw err;
+        assert.strictEqual(320, features.width);
+        assert.strictEqual(240, features.height);
+        done();
+      });
+    });
+  },
+  function(done) {
     sharp.resize(inputJpg, outputJpg, 320, -1, function(err) {
       if (err) throw err;
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
         assert.strictEqual(262, features.height);
+        done();
       });
-
-      sharp.resize(inputJpg, outputJpg, -1, 320, function(err) {
-        if (err) throw err;
-        imagemagick.identify(outputJpg, function(err, features) {
-          if (err) throw err;
-          assert.strictEqual(392, features.width);
-          assert.strictEqual(320, features.height);
-        });
-      });
-
     });
-  });
-});
+  },
+  function(done) {
+    sharp.resize(inputJpg, outputJpg, -1, 320, function(err) {
+      if (err) throw err;
+      imagemagick.identify(outputJpg, function(err, features) {
+        if (err) throw err;
+        assert.strictEqual(392, features.width);
+        assert.strictEqual(320, features.height);
+        done();
+      });
+    });
+  },
+  function(done) {
+    sharp.resize(inputJpg, outputJpg, -1, -1, function(err) {
+      if (err) throw err;
+      imagemagick.identify(outputJpg, function(err, features) {
+        if (err) throw err;
+        assert.strictEqual(2725, features.width);
+        assert.strictEqual(2225, features.height);
+        done();
+      });
+    });
+  }
+]);