fix fd0 read error on long stdout output (scanner buffer was too small)

cmdext/cmdrunner.go

@@ -36,8 +36,9 @@ func run(opt CommandRunner) (CommandResult, error) {
 	}
 
 	preader := pipeReader{
-		stdout: stdoutPipe,
+		lineBufferSize: langext.Ptr(128 * 1024 * 1024), // 128MB max size of a single line, is hopefully enough....
-		stderr: stderrPipe,
+		stdout:         stdoutPipe,
+		stderr:         stderrPipe,
 	}
 
 	err = cmd.Start()
@@ -60,14 +61,17 @@ func run(opt CommandRunner) (CommandResult, error) {
 		stdout, stderr, stdcombined, err := preader.Read(opt.listener)
 		if err != nil {
 			outputChan <- resultObj{stdout, stderr, stdcombined, err}
+			_ = cmd.Process.Kill()
+			return
 		}
 
 		err = cmd.Wait()
 		if err != nil {
 			outputChan <- resultObj{stdout, stderr, stdcombined, err}
+		} else {
+			outputChan <- resultObj{stdout, stderr, stdcombined, nil}
 		}
 
-		outputChan <- resultObj{stdout, stderr, stdcombined, nil}
 	}()
 
 	var timeoutChan <-chan time.Time = make(chan time.Time, 1)

cmdext/cmdrunner_test.go

@@ -280,7 +280,7 @@ func TestLongStdout(t *testing.T) {
 	if res1.StdErr != "" {
 		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
 	}
-	if len(res1.StdOut) != 375006 {
+	if len(res1.StdOut) != 375009 {
 		t.Errorf("len(res1.StdOut) == '%v'", len(res1.StdOut))
 	}
 

cmdext/pipereader.go

@@ -8,8 +8,9 @@ import (
 )
 
 type pipeReader struct {
-	stdout io.ReadCloser
+	lineBufferSize *int
-	stderr io.ReadCloser
+	stdout         io.ReadCloser
+	stderr         io.ReadCloser
 }
 
 // Read ready stdout and stdin until finished
@@ -33,7 +34,6 @@ func (pr *pipeReader) Read(listener []CommandListener) (string, string, string,
 		buf := make([]byte, 128)
 		for true {
 			n, out := pr.stdout.Read(buf)
-
 			if n > 0 {
 				txt := string(buf[:n])
 				stdout += txt
@@ -91,6 +91,9 @@ func (pr *pipeReader) Read(listener []CommandListener) (string, string, string,
 	wg.Add(1)
 	go func() {
 		scanner := bufio.NewScanner(stdoutBufferReader)
+		if pr.lineBufferSize != nil {
+			scanner.Buffer([]byte{}, *pr.lineBufferSize)
+		}
 		for scanner.Scan() {
 			txt := scanner.Text()
 			for _, lstr := range listener {
@@ -98,6 +101,9 @@ func (pr *pipeReader) Read(listener []CommandListener) (string, string, string,
 			}
 			combch <- combevt{txt, false}
 		}
+		if err := scanner.Err(); err != nil {
+			errch <- err
+		}
 		combch <- combevt{"", true}
 		wg.Done()
 	}()
@@ -107,6 +113,9 @@ func (pr *pipeReader) Read(listener []CommandListener) (string, string, string,
 	wg.Add(1)
 	go func() {
 		scanner := bufio.NewScanner(stderrBufferReader)
+		if pr.lineBufferSize != nil {
+			scanner.Buffer([]byte{}, *pr.lineBufferSize)
+		}
 		for scanner.Scan() {
 			txt := scanner.Text()
 			for _, lstr := range listener {
@@ -114,6 +123,9 @@ func (pr *pipeReader) Read(listener []CommandListener) (string, string, string,
 			}
 			combch <- combevt{txt, false}
 		}
+		if err := scanner.Err(); err != nil {
+			errch <- err
+		}
 		combch <- combevt{"", true}
 		wg.Done()
 	}()