narrow escape

check.sh

@@ -8,6 +8,7 @@ tests="
 00-exit
 00-exit-0
 00-exit-1
+00-exit-2
 
 01-script-newline
 01-script-semi

gash/grammar.scm

@@ -169,8 +169,10 @@
      ltest            <   '['
      rtest            <   ']'
 
-     literal          <-  !reserved (!']' ![ \t\v\f\n`'\")};|&$] (escape / .))+
-     escape           <-  '\\' [ \"$]
+     literal          <-  !reserved (escaped / !allowed .)+
+     escaped          <-  escape [ \"$]
+     escape           <   [\\]
+     allowed          <-  ']' / [ \t\v\f\n`'\")};|&$] / '\\\n'
 
      identifier       <-  [_a-zA-Z][_a-zA-Z0-9]*
 

test/00-exit-2.exit

@@ -0,0 +1 @@
+2

test/00-exit-2.sh

@@ -0,0 +1 @@
+exit 2

test/01-script-backslash.exit

@@ -1 +1 @@
-2
+0

test/01-script-backslash.sh

@@ -1,2 +1,2 @@
 exit\
-    2
+    0