Source:        a*b\*c
Replace str:   _\\_\z_
Pattern:       single backslash and star: "replace literal star"
Unquoted:      a_\_z_b\*c
Unquoted =:    a_\_z_b\*c
Quoted:        a_\_z_b\*c
Quoted =:      a_\_z_b\*c
Pattern:       double backslash and star: "replace backslash and everything after it"
Unquoted:      a*b_\_z_
Unquoted =:    a*b_\_z_
Quoted:        a*b_\_z_
Quoted =:      a*b_\_z_

Source:        a\bc
Replace str:   _\\_\z_
Pattern:       single backslash and b: "replace b"
Unquoted:      a\_\_z_c
Unquoted =:    a\_\_z_c
Quoted:        a\_\_z_c
Quoted =:      a\_\_z_c
Pattern:       double backslash and b: "replace backslash and b"
Unquoted:      a_\_z_c
Unquoted =:    a_\_z_c
Quoted:        a_\_z_c
Quoted =:      a_\_z_c

Source:        a\bc
Replace str:   _\\_\z_ (as variable $s)
Pattern:       single backslash and b: "replace b"
Unquoted:      a\_\\_\z_c
Unquoted =:    a\_\\_\z_c
Quoted:        a\_\\_\z_c
Quoted =:      a\_\\_\z_c
Pattern:       double backslash and b: "replace backslash and b"
Unquoted:      a_\\_\z_c
Unquoted =:    a_\\_\z_c
Quoted:        a_\\_\z_c
Quoted =:      a_\\_\z_c

Done: 0