Support custom names for "browser" field resolution

Fixes: #1917

index.js

@@ -83,12 +83,19 @@ function Browserify (files, opts) {
     self._transforms = [];
     self._entryOrder = 0;
     self._ticked = false;
-    self._bresolve = opts.browserField === false
+
+    var browserField = opts.browserField
+    self._bresolve = browserField === false
         ? function (id, opts, cb) {
             if (!opts.basedir) opts.basedir = path.dirname(opts.filename)
             resolve(id, opts, cb)
         }
-        : bresolve
+        : typeof browserField === 'string'
+            ? function (id, opts, cb) {
+                opts.browser = browserField
+                bresolve(id, opts, cb)
+            }
+            : bresolve
     ;
     self._syntaxCache = {};
 

readme.markdown

@@ -447,7 +447,9 @@ useful for preserving the original paths that a bundle was generated with.
 `opts.bundleExternal` boolean option to set if external modules should be
 bundled. Defaults to true.
 
-When `opts.browserField` is false, the package.json browser field will be ignored.
+When `opts.browserField` is false, the package.json browser field will be
+ignored. When `opts.browserField` is set to a `string`, then a custom field name
+can be used instead of the default `"browser"` field.
 
 When `opts.insertGlobals` is true, always insert `process`, `global`,
 `__filename`, and `__dirname` without analyzing the AST for faster builds but