Do not count length when maxBuffer is Infinity

This reflects the changes in nodejs/node#43822

Author: fasttime

lib/foreground-exec-async.js

@@ -109,26 +109,29 @@ function execFileWithStdIO
         {
             if (encoding)
                 stream.setEncoding(encoding);
-            stream.on
-            (
-                'data',
-                chunk =>
+            const listener =
+            maxBuffer === Infinity ?
+            chunk =>
+            {
+                chunks.push(chunk);
+            } :
+            chunk =>
+            {
+                const encoding = stream.readableEncoding;
+                const length = encoding ? Buffer.byteLength(chunk, encoding) : chunk.length;
+                const available = maxBuffer - chunks.byteLength;
+                if (length > available)
                 {
-                    const encoding = stream.readableEncoding;
-                    const length = encoding ? Buffer.byteLength(chunk, encoding) : chunk.length;
-                    const available = maxBuffer - chunks.byteLength;
-                    if (length > available)
-                    {
-                        chunks.push(chunk.slice(0, available));
-                        error = new RangeError(`${name}, maxBuffer length exceeded`);
-                        error.code = 'ERR_CHILD_PROCESS_STDIO_MAXBUFFER';
-                        kill();
-                    }
-                    else
-                        chunks.push(chunk);
-                    chunks.byteLength += length;
-                },
-            );
+                    chunks.push(chunk.slice(0, available));
+                    error = new RangeError(`${name}, maxBuffer length exceeded`);
+                    error.code = 'ERR_CHILD_PROCESS_STDIO_MAXBUFFER';
+                    kill();
+                }
+                else
+                    chunks.push(chunk);
+                chunks.byteLength += length;
+            };
+            stream.on('data', listener);
         }
         return chunks;
     }

test/exec.spec.js

@@ -249,6 +249,21 @@ describe
                     () => testMaxBuffer('stdout', 'ascii', 'l\'archiviazione C'),
                 );
 
+                it
+                (
+                    'on stdout with value `Infinity`',
+                    async () =>
+                    {
+                        const { stdout } =
+                        await c8js.exec
+                        (
+                            joinPath('test/fixtures/stdout-max-buffer-test.js'),
+                            { maxBuffer: Infinity, silent: true, tempDirectory },
+                        );
+                        assert.equal(stdout, 'l\'archiviazione è riuscita\n');
+                    },
+                );
+
                 it
                 (
                     'on stderr with `buffer` encoding',
@@ -272,6 +287,21 @@ describe
                     'on stderr with `ascii` encoding',
                     () => testMaxBuffer('stderr', 'ascii', 'es liegt eine StC'),
                 );
+
+                it
+                (
+                    'on stderr with value `Infinity`',
+                    async () =>
+                    {
+                        const { stderr } =
+                        await c8js.exec
+                        (
+                            joinPath('test/fixtures/stderr-max-buffer-test.js'),
+                            { maxBuffer: Infinity, silent: true, tempDirectory },
+                        );
+                        assert.equal(stderr, 'es liegt eine Störung vor\n');
+                    },
+                );
             },
         );