[Bug]: Fabric ignores lines without trailing newline on stdin

[kolewu]

What happened?

A line without a trailing newline will be ignored:

echo -n "light nuts wall" | fabric --dry-run

No user input is sent:

Dry run: Would send the following request:
Options:

With a trailing newline it works:

echo "light nuts wall" | fabric --dry-run

User input is sent:

Dry run: Would send the following request:
User:
light nuts wall

Options:

Version check

• Yes I was.

Relevant log output

No response

Relevant screenshots (optional)

No response

[kolewu]

Fix is so simple that I don't want to make a MR for it. Just add the data up to EOF when reading stdin. That is in cli/flags.go in function readStdin():

 // readStdin reads from stdin and returns the input as a string or an error
 func readStdin() (string, error) {
     reader := bufio.NewReader(os.Stdin)
     var input string
     for {
         line, err := reader.ReadString('\n')
+        input += line
          if err != nil {
             if errors.Is(err, io.EOF) {
                 break
             }
             return "", fmt.Errorf("error reading from stdin: %w", err)
         }
-        input += line
     }
     return input, nil
 }

Since I'm just a Go beginner, I'm not sure, if line must be checked before using it.

This change fixes the described problem and also #917.

[techjp]

I thought I was going insane when experiencing this problem after migrating from the old Python version of Fabric to the new Go version!

For those who do not wish to change the code, you can do this as a workaround until the bug is fixed:

(cat <filename here>; echo "") | fabric <rest of fabric command>