Fix double click to zoom causing a pan

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2020 Andrew Seigner
+Copyright 2021 Andrew Seigner
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -69,28 +69,18 @@ deserve calling out:
 - warning on spinner requests can take up to 1 minute
 - show "Last refresh" time
 - make fonts bigger / easier to read
-- fix double click to zoom changing center / viewport limits
 - fix thumbnail click to move not tracking the click point exactly
 - fix http://localhost:8888/?repo=github.com/kubernetes/kubernetes&cluster=true
-- deterministic repo location, with cli flag
-- use bin/goda
-- don't default to master.info
-- faster, replace Download
-  - golang.org/x/tools/go/vcs or
-  - https://github.com/gojp/goreportcard/blob/master/download/download.go
-  - OR: use existing proxy, then fall back to vcs/download.go
+- deterministic repo location, with cli flag?
 - don't shell out
 - landing page
 - prod
-  - default to this repo
-  - remove or repurpose localhost URLs in readme
   - monitoring, cache hits/misses
 - graphs by repo revision
 - fix new svg loading on firefox
 - prevent normal dragging on mobile
 - fix thumbnail resize/refresh jitter
 - fix irc logo thumbnail border aspect ratio
 - show progress during repo compile
-- generic svg and dot support, paste and url
 - consider capturing all mouse scrolling over every element
 - on drag mouseup, don't open godoc link

public/js/gographs.js

@@ -238,7 +238,12 @@ function between(val, a, b) {
   }
 }
 
-function beforePan(_, newPan){
+function beforePan(oldPan, newPan){
+  if (oldPan.x == newPan.x && oldPan.y == newPan.y) {
+    // zoom, not a pan
+    return newPan;
+  }
+
   const sizes = this.getSizes();
   const viewportRect = DOM.viewport.getBoundingClientRect();