diff --git a/b2/test/subesc b/b2/test/subesc
index 2d38362..9155589 100755
--- a/b2/test/subesc
+++ b/b2/test/subesc
@@ -1,9 +1,23 @@
 #!/bin/bash
 . ./Common
 
+#
+# Note that we have to escape things for the shell as well. In general,
+# for any character C, \C becomes C. However, in the case of <<EOF ... EOF,
+# \ is left as is if it doesn't precede a special character.
+#
+
 ###############################################################################
 
-tst "substitutions: escape *" -R '*\\*' <<EOF
+tst "substitutions: escape x in regexp" -R '*\\x' <<EOF
+EOF
+
+expect <<EOF
+^.*\\x\$
+EOF
+
+#------------------------------------------------------------------------------
+tst "substitutions: escape * in regexp" -R '*\\*' <<EOF
 EOF
 
 expect <<EOF
@@ -12,7 +26,7 @@ EOF
 
 #------------------------------------------------------------------------------
 
-tst "substitutions: escape . (implicit)" -R 'x.y' <<EOF
+tst "substitutions: escape . in regexp (implicit)" -R 'x.y' <<EOF
 EOF
 
 expect <<EOF
@@ -21,7 +35,7 @@ EOF
 
 #------------------------------------------------------------------------------
 
-tst "substitutions: escape |" -R 'a\\\|b' <<EOF
+tst "substitutions: escape | in regexp" -R 'a\\\|b' <<EOF
 EOF
 
 expect <<EOF
@@ -30,7 +44,7 @@ EOF
 
 #------------------------------------------------------------------------------
 
-tst "substitutions: escape \\" -R 'x\\\\y' <<EOF
+tst "substitutions: escape \\ in regexp" -R 'x\\\\y' <<EOF
 EOF
 
 expect <<EOF
@@ -39,11 +53,90 @@ EOF
 
 #------------------------------------------------------------------------------
 
-tst_fail "substitutions: escape EOL" -R 'x\\' <<EOF
+tst_fail "substitutions: try to escape EOL in regexp" -R 'x\\' <<EOF
 EOF
 
 expect <<EOF
 dummy:2: regexp ends with backslash
 EOF
 
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape space in regexp (match)" -q '"x=a c"' <<EOF
+!-s
+y=a
+x=a\ c { y=b }
+EOF
+
+expect <<EOF
+y=b
+EOF
+
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape space in regexp (no match)" -q '"x=a b"' <<EOF
+!-s
+y=a
+x=a\ c { y=b }
+EOF
+
+expect <<EOF
+y=a
+EOF
+
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape \$ in value" -q <<EOF
+!-s
+x=y\\$
+EOF
+
+expect <<EOF
+x=y\$
+EOF
+
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape x in value" -q <<EOF
+!-s
+x=y\x
+EOF
+
+expect <<EOF
+x=yx
+EOF
+
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape space in value" -q <<EOF
+!-s
+x=x\ y
+EOF
+
+expect <<EOF
+x=x y
+EOF
+
+#------------------------------------------------------------------------------
+
+tst "substitutions: escape \\ in value" -q <<EOF
+!-s
+x=a\\\\b
+EOF
+
+expect <<EOF
+x=a\\b
+EOF
+
+#------------------------------------------------------------------------------
+
+tst_fail "substitutions: try to escape EOL in value" -q <<EOF
+!-s
+x=y\\
+EOF
+
+expect <<EOF
+s:1: syntax error
+EOF
+
 ###############################################################################