ash: fix ${var/s/r} handling, add testcase.
diff --git a/shell/ash_test/ash-vars/var_bash3.tests b/shell/ash_test/ash-vars/var_bash3.tests
new file mode 100755
index 0000000..b905027
--- /dev/null
+++ b/shell/ash_test/ash-vars/var_bash3.tests
@@ -0,0 +1,41 @@
+a='abc'
+r=${a//b/\041#}
+echo $r
+echo ${a//b/\041#}
+echo "${a//b/\041#}"
+
+a='abc'
+r=${a//b/\\041#}
+echo $r
+echo ${a//b/\\041#}
+echo "${a//b/\\041#}"
+
+a='abc'
+b='\041#'
+r=${a//b/$b}
+echo $r
+echo ${a//b/$b}
+echo "${a//b/$b}"
+
+a='abc'
+b='\'
+r="${a//b/$b}"
+echo $r
+echo ${a//b/$b}
+echo "${a//b/$b}"
+
+a='abc'
+b='\\'
+r="${a//b/$b}"
+echo $r
+echo ${a//b/$b}
+echo "${a//b/$b}"
+
+a='abc'
+b='\t'
+r="${a//b/$b}"
+echo $r
+echo ${a//b/$b}
+echo "${a//b/$b}"
+echo ${a//b/\t}
+echo "${a//b/\t}"