2.8.8 can break recursive function calls

[pfhayes]

When minifying the following function

module.exports = function outer() {
  var myFunction = function myFunction() {                                                                       
      myFunction();
  };
  myFunction();
};

with the following incantation

./node_modules/.bin/uglifyjs --compress '' file.js -o minified.js

Then the following warning will be emitted: WARN: Dropping unused variable myFunction

This is not correct, because the variable is used inside the recursive call. Furthermore, this will generate invalid code that references myFunction inside the function call and you will get an undefined variable error at runtime

We've confirmed that this broke in the most recent build (2.8.8)

[pfhayes]

Original example was a bit too simple, updated to reflect real minimal example

[kzc]

Temporary 2.8.8 workaround - use uglifyjs -c reduce_vars=false

WARN: Collapsing variable myFunction [-:6,2]

module.exports = function() {
    !function myFunction() {
        myFunction();
    }();
};

[kzc]

Duplicate: #1573

[kzc]

@alexlamsl This appears to fix it:

--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2611,9 +2611,6 @@ merge(Compressor.prototype, {
                 if (compressor.option("unused")
                     && def.references.length == 1
                     && compressor.find_parent(AST_Scope) === def.scope) {
-                    if (!compressor.option("keep_fnames")) {
-                        exp.name = null;
-                    }
                     self.expression = exp;
                 }
             }

[alexlamsl]

@pfhayes @kzc thanks for spotting this! PR coming right up...