Ruby: Fix regex parsing of /[|]/

hvitved · hvitved · commit 6d4eecff14c8 · 2022-03-08T09:52:06.000+01:00
diff --git a/ruby/ql/lib/codeql/ruby/security/performance/ParseRegExp.qll b/ruby/ql/lib/codeql/ruby/security/performance/ParseRegExp.qll
@@ -861,6 +861,7 @@ abstract class RegExp extends AST::StringlikeLiteral {
    * Whether the text in the range start,end is an alternation
    */
   predicate alternation(int start, int end) {
+    not this.inCharSet(start) and
     this.topLevel(start, end) and
     exists(int less | this.subalternation(start, less, _) and less < end)
   }
diff --git a/ruby/ql/test/library-tests/regexp/parse.expected b/ruby/ql/test/library-tests/regexp/parse.expected
@@ -181,11 +181,8 @@ regexp.rb:
 #   26| [RegExpConstant, RegExpNormalChar] -
 
 #   27| [RegExpCharacterClass] [|]
-#-----| 0 -> [RegExpAlt] |
 #-----| 0 -> [RegExpConstant, RegExpNormalChar] |
 
-#   27| [RegExpAlt] |
-
 #   27| [RegExpConstant, RegExpNormalChar] |
 
 #   30| [RegExpCharacterClass] [[a-f]

Original file line number	Diff line number	Diff line change
`@@ -861,6 +861,7 @@ abstract class RegExp extends AST::StringlikeLiteral {`
`861`	`861`	`* Whether the text in the range start,end is an alternation`
`862`	`862`	`*/`
`863`	`863`	`predicate alternation(int start, int end) {`
	`864`	`+ not this.inCharSet(start) and`
`864`	`865`	`this.topLevel(start, end) and`
`865`	`866`	`exists(int less \| this.subalternation(start, less, _) and less < end)`
`866`	`867`	`}`