Allow input density range up to 100000 DPI (#2348)

lib/input.js

@@ -57,10 +57,10 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
     }
     // Density
     if (is.defined(inputOptions.density)) {
-      if (is.inRange(inputOptions.density, 1, 2400)) {
+      if (is.inRange(inputOptions.density, 1, 100000)) {
         inputDescriptor.density = inputOptions.density;
       } else {
-        throw is.invalidParameterError('density', 'number between 1 and 2400', inputOptions.density);
+        throw is.invalidParameterError('density', 'number between 1 and 100000', inputOptions.density);
       }
     }
     // limitInputPixels

test/fixtures/circle.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 8 8">
+      <circle r="3.75" cx="4" cy="4" fill="deeppink" />
+</svg>

test/fixtures/index.js

@@ -107,6 +107,7 @@ module.exports = {
   inputGifAnimated: getPath('rotating-squares.gif'), // CC0 https://loading.io/spinner/blocks/-rotating-squares-preloader-gif
   inputGifAnimatedLoop3: getPath('animated-loop-3.gif'), // CC-BY-SA-4.0 Petrus3743 https://commons.wikimedia.org/wiki/File:01-Goldener_Schnitt_Formel-Animation.gif
   inputSvg: getPath('check.svg'), // http://dev.w3.org/SVG/tools/svgweb/samples/svg-files/check.svg
+  inputSvgSmallViewBox: getPath('circle.svg'),
   inputSvgWithEmbeddedImages: getPath('struct-image-04-t.svg'), // https://dev.w3.org/SVG/profiles/1.2T/test/svg/struct-image-04-t.svg
 
   inputJPGBig: getPath('flowers.jpeg'),

test/unit/io.js

@@ -647,7 +647,7 @@ describe('Input/output', function () {
     it('Invalid density: string', function () {
       assert.throws(function () {
         sharp({ density: 'zoinks' });
-      }, /Expected number between 1 and 2400 for density but received zoinks of type string/);
+      }, /Expected number between 1 and 100000 for density but received zoinks of type string/);
     });
     it('Setting animated property updates pages property', function () {
       assert.strictEqual(sharp({ animated: false }).options.input.pages, 1);

test/unit/svg.js

@@ -48,6 +48,31 @@ describe('SVG input', function () {
       });
   });
 
+  it('Convert SVG to PNG at DPI larger than 2400', function (done) {
+    const size = 1024;
+    sharp(fixtures.inputSvgSmallViewBox).metadata(function (err, metadata) {
+      if (err) throw err;
+      const density = (size / Math.max(metadata.width, metadata.height)) * metadata.density;
+      sharp(fixtures.inputSvgSmallViewBox, { density })
+        .resize(size)
+        .toFormat('png')
+        .toBuffer(function (err, data, info) {
+          if (err) throw err;
+          assert.strictEqual('png', info.format);
+          assert.strictEqual(size, info.width);
+          assert.strictEqual(size, info.height);
+          fixtures.assertSimilar(fixtures.expected('circle.png'), data, function (err) {
+            if (err) throw err;
+            sharp(data).metadata(function (err, info) {
+              if (err) throw err;
+              assert.strictEqual(9216, info.density);
+              done();
+            });
+          });
+        });
+    });
+  });
+
   it('Convert SVG to PNG at 14.4DPI', function (done) {
     sharp(fixtures.inputSvg, { density: 14.4 })
       .toFormat('png')