fix(gatsby-plugin-sharp): return correct height (#25150)

Co-authored-by: Ward Peeters <[email protected]>

Author: imakida

packages/gatsby-plugin-sharp/src/__tests__/__snapshots__/index.js.snap

@@ -789,38 +789,38 @@ Array [
           Object {
             "args": Object {
               "fit": "inside",
-              "height": 50,
+              "height": 34,
               "toFormat": "png",
               "width": 50,
             },
-            "outputPath": "d9f78/test.png",
+            "outputPath": "45628/test.png",
           },
           Object {
             "args": Object {
               "fit": "inside",
-              "height": 100,
+              "height": 68,
               "toFormat": "png",
               "width": 100,
             },
-            "outputPath": "997ba/test.png",
+            "outputPath": "52a18/test.png",
           },
           Object {
             "args": Object {
               "fit": "inside",
-              "height": 200,
+              "height": 136,
               "toFormat": "png",
               "width": 200,
             },
-            "outputPath": "6ad4e/test.png",
+            "outputPath": "279d8/test.png",
           },
           Object {
             "args": Object {
               "fit": "inside",
-              "height": 281,
+              "height": 191,
               "toFormat": "png",
               "width": 281,
             },
-            "outputPath": "7aa47/test.png",
+            "outputPath": "24238/test.png",
           },
         ],
         "pluginOptions": Object {

packages/gatsby-plugin-sharp/src/index.js

@@ -544,7 +544,13 @@ async function fluid({ file, args = {}, reporter, cache }) {
     }
 
     if (options.maxWidth !== undefined && options.maxHeight !== undefined) {
-      arrrgs.height = Math.round(size * (options.maxHeight / options.maxWidth))
+      if (options.fit === sharp.fit.inside) {
+        arrrgs.height = Math.round(size * (maxHeight / maxWidth))
+      } else {
+        arrrgs.height = Math.round(
+          size * (options.maxHeight / options.maxWidth)
+        )
+      }
     }
 
     return arrrgs