fix issues uncovered by lgtm (#4749)

2 files changed, 37 insertions, 32 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 0069570c..349dad90 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -277,7 +277,7 @@ merge(Compressor.prototype, {
                     export_symbol(stat.name);
                 }
             } else if (stat instanceof AST_ExportReferences) {
-                body.splice(i, 1);
+                body.splice(i--, 1);
                 [].push.apply(props, stat.properties);
             }
         }
@@ -773,10 +773,10 @@ merge(Compressor.prototype, {
             //   (function(a,b) {...})(c,d) ---> (function() {var a=c,b=d; ...})()
             // So existing transformation rules can work on them.
             var safe = !fn.uses_arguments || tw.has_directive("use strict");
-            fn.argnames.forEach(function(arg, i) {
+            fn.argnames.forEach(function(argname, i) {
                 var value = iife.args[i];
-                scan_declaration(tw, compressor, arg, function() {
-                    var j = fn.argnames.indexOf(arg);
+                scan_declaration(tw, compressor, argname, function() {
+                    var j = fn.argnames.indexOf(argname);
                     var arg = j < 0 ? value : iife.args[j];
                     if (arg instanceof AST_Sequence && arg.expressions.length < 2) arg = arg.expressions[0];
                     return arg || make_node(AST_Undefined, iife);
@@ -1889,24 +1889,21 @@ merge(Compressor.prototype, {
                         var def = lhs.definition();
                         var referenced = def.references.length - def.replaced;
                         if (candidate instanceof AST_Assign) referenced--;
-                        if (replaced && referenced == replaced) {
-                            abort = false;
-                        } else {
+                        if (!replaced || referenced > replaced) {
                             candidates.push(hit_stack);
                             force_single = true;
                             continue;
                         }
-                        if (replaced) {
-                            hit_index = 0;
-                            hit = funarg;
-                            for (var i = stat_index; !abort && i < statements.length; i++) {
-                                if (!statements[i].transform(multi_replacer)) statements.splice(i--, 1);
-                            }
-                            if (candidate instanceof AST_VarDef) {
-                                replaced = !compressor.exposed(def) && def.references.length == def.replaced;
-                            }
-                            value_def.single_use = false;
+                        abort = false;
+                        hit_index = 0;
+                        hit = funarg;
+                        for (var i = stat_index; !abort && i < statements.length; i++) {
+                            if (!statements[i].transform(multi_replacer)) statements.splice(i--, 1);
+                        }
+                        if (candidate instanceof AST_VarDef) {
+                            replaced = !compressor.exposed(def) && def.references.length == def.replaced;
                         }
+                        value_def.single_use = false;
                     }
                     if (replaced && !remove_candidate(candidate)) statements.splice(stat_index, 1);
                 }
@@ -6927,20 +6924,14 @@ merge(Compressor.prototype, {
                     value = value.drop_side_effect_free(compressor);
                     node.value = value ? make_sequence(node.value, [
                         value,
-                        make_node(AST_Number, node.value, {
-                            value: 0
-                        })
+                        make_node(AST_Number, node.value, { value: 0 }),
                     ]) : null;
-                } else if (ev && !(ev instanceof AST_Node)) {
+                } else if (!(ev instanceof AST_Node)) {
                     value = value.drop_side_effect_free(compressor);
                     node.value = value ? make_sequence(node.value, [
                         value,
-                        make_node(AST_Number, node.value, {
-                            value: 1
-                        })
-                    ]) : make_node(AST_Number, node.value, {
-                        value: 1
-                    });
+                        make_node(AST_Number, node.value, { value: 1 }),
+                    ]) : make_node(AST_Number, node.value, { value: 1 });
                 }
             }
         });
@@ -8397,7 +8388,7 @@ merge(Compressor.prototype, {
                         continue;
                     }
                 }
-            } else if (argname && drop_fargs(argname, args[i])) {
+            } else if (drop_fargs(argname, args[i])) {
                 var node = args[i].drop_side_effect_free(compressor);
                 fn.argnames.splice(i, 1);
                 args.splice(i, 1);
@@ -11469,9 +11460,7 @@ merge(Compressor.prototype, {
                 value.key = "" + value.key.value;
             }
         }
-        return changed ? make_node(AST_Object, self, {
-            properties: values
-        }) :  self;
+        return make_node(AST_Object, self, { properties: values });
 
         function flush() {
             keys.each(function(props) {
diff --git a/test/compress/exports.js b/test/compress/exports.js
index a7239148..3aaae4ae 100644
--- a/test/compress/exports.js
+++ b/test/compress/exports.js
@@ -203,7 +203,23 @@ mangle_rename: {
     }
 }
 
-hoist_exports: {
+hoist_exports_1: {
+    options = {
+        hoist_exports: true,
+    }
+    input: {
+        export { a };
+        export var b;
+        export function f() {}
+    }
+    expect: {
+        var b;
+        function f() {}
+        export { a, b, f };
+    }
+}
+
+hoist_exports_2: {
     options = {
         evaluate: true,
         hoist_exports: true,