suppress false positives from fuzzer (#3638)

test/ufuzz/index.js

@@ -1089,6 +1089,19 @@ function log(options) {
     }
 }
 
+function fuzzy_match(original, uglified) {
+    original = original.split(" ", 5);
+    uglified = uglified.split(" ", 5);
+    for (var i = 0; i < 5; i++) {
+        if (original[i] === uglified[i]) continue;
+        var a = +original[i];
+        var b = +uglified[i];
+        if (Math.abs((b - a) / a) < 1e-10) continue;
+        return false;
+    }
+    return true;
+}
+
 var fallback_options = [ JSON.stringify({
     compress: false,
     mangle: false
@@ -1111,8 +1124,12 @@ for (var round = 1; round <= num_iterations; round++) {
             uglify_code = uglify_code.code;
             uglify_result = sandbox.run_code(uglify_code, o.toplevel);
             ok = sandbox.same_stdout(original_result, uglify_result);
-            if (!ok && o.compress.unsafe_math) {
-                ok = sandbox.same_stdout(sandbox.run_code(original_code.replace(/( - 0\.1){3}/g, " - 0.3")), uglify_result, o.toplevel);
+            if (!ok && typeof uglify_result == "string" && o.compress.unsafe_math) {
+                ok = fuzzy_match(original_result, uglify_result);
+                if (!ok) {
+                    var fuzzy_result = sandbox.run_code(original_code.replace(/( - 0\.1){3}/g, " - 0.3"));
+                    ok = sandbox.same_stdout(fuzzy_result, uglify_result, o.toplevel);
+                }
             }
         } else {
             uglify_code = uglify_code.error;

test/ufuzz/job.js

@@ -12,17 +12,16 @@ function spawn(endTime) {
     ], {
         stdio: [ "ignore", "pipe", "pipe" ]
     }).on("exit", respawn);
-    var line = "";
+    var stdout = "";
     child.stdout.on("data", function(data) {
-        line += data;
+        stdout += data;
     });
-    child.stderr.once("data", function() {
-        process.exitCode = 1;
-    }).pipe(process.stdout);
+    var stderr = "";
+    child.stderr.on("data", trap).pipe(process.stdout);
     var keepAlive = setInterval(function() {
-        var end = line.lastIndexOf("\r");
-        console.log(line.slice(line.lastIndexOf("\r", end - 1) + 1, end));
-        line = line.slice(end + 1);
+        var end = stdout.lastIndexOf("\r");
+        console.log(stdout.slice(stdout.lastIndexOf("\r", end - 1) + 1, end));
+        stdout = stdout.slice(end + 1);
     }, ping);
     var timer = setTimeout(function() {
         clearInterval(keepAlive);
@@ -31,9 +30,17 @@ function spawn(endTime) {
     }, endTime - Date.now());
 
     function respawn() {
-        console.log(line);
+        console.log(stdout.replace(/[^\r\n]*\r/g, ""));
         clearInterval(keepAlive);
         clearTimeout(timer);
         spawn(endTime);
     }
+
+    function trap(data) {
+        stderr += data;
+        if (~stderr.indexOf("\nminify(options):\n")) {
+            process.exitCode = 1;
+            child.stderr.removeListener("data", trap);
+        }
+    }
 }