FindHelperBinary will try LookPath of absolute path

exec.LookPath seems to handle absolute paths gracefully. On Windows this
allows to additionally check for all known executable alternatives
when only name is provided.

Signed-off-by: Arthur Sengileyev <[email protected]>

pkg/config/config.go

@@ -1332,9 +1332,14 @@ func (c *Config) FindHelperBinary(name string, searchPATH bool) (string, error)
 				path = filepath.Join(bindirPath, strings.TrimPrefix(path, bindirPrefix+string(filepath.Separator)))
 			}
 		}
-		fullpath := filepath.Join(path, name)
-		if fi, err := os.Stat(fullpath); err == nil && fi.Mode().IsRegular() {
-			return fullpath, nil
+		// Absolute path will force exec.LookPath to check for binary existence instead of lookup everywhere in PATH
+		abspath, err := filepath.Abs(filepath.Join(path, name))
+		if err == nil {
+			// exec.LookPath from absolute path on Unix is equal to os.Stat + IsNotDir + check for executable bits in FileMode
+			// exec.LookPath from absolute path on Windows is equal to os.Stat + IsNotDir for `file.ext` or loops through extensions from PATHEXT for `file`
+			if lp, err := exec.LookPath(abspath); err == nil {
+				return lp, nil
+			}
 		}
 	}
 	if searchPATH {