fix: count(text.splitAt()) does not account for all lines, use max(text.splitAt(,i)) instead

Author: Alvaro Muñoz

ql/lib/codeql/actions/ast/internal/Ast.qll

@@ -4,20 +4,24 @@ private import codeql.actions.Helper
 private import codeql.actions.config.Config
 private import codeql.actions.DataFlow
 
+bindingset[text]
+int numberOfLines(string text) { result = max(int i | exists(text.splitAt("\n", i))) }
+
 /**
  * Gets the length of each line in the StringValue .
  */
 bindingset[text]
-int lineLength(string text, int idx) {
-  exists(string line | line = text.splitAt("\n", idx) and result = line.length() + 1)
+int lineLength(string text, int i) {
+  i in [0 .. numberOfLines(text)] and
+  result = text.splitAt("\n", i).length() + 1
 }
 
 /**
  * Gets the sum of the length of the lines up to the given index.
  */
 bindingset[text]
 int partialLineLengthSum(string text, int i) {
-  i in [0 .. count(text.splitAt("\n"))] and
+  i in [0 .. numberOfLines(text)] and
   result = sum(int j, int length | j in [0 .. i] and length = lineLength(text, j) | length)
 }