[Alexandre Kohler (kwy404)]

Root cause: PositionToOffset.convert in src/common/stringUtils.ts is meant to clamp any line past the end of the source to source.length (the existing test expects line 10 of '\nhello\nworld\n' to give 13). The guard uses lineNumber > this.lines.length, so a line number equal to this.lines.length slips through, this.lines[lineNumber] is undefined, and the result is NaN. For example new PositionToOffset('hello\nworld').convert(new Base0Position(2, 0)) returns NaN instead of 11. With a NaN offset the REPL completions match no node, and extractScopeRenames assigns it to a sticky regex lastIndex, which reads it as 0 and picks up the identifier at the start of the file. getLineOffset in the same class already uses >=.

Fix: change the guard to >=, matching getLineOffset.

Test: added two assertions to the existing positionToOffset test in src/common/stringUtils.test.ts for the line right after the last one. They fail before the change (expected NaN to equal 11) and pass after.

• Ran: npm run test:unit. The only difference from main is the fixed test (the NodeBinaryProvider failures are local environment ones and happen on main too).
• Ran: npm run test:types, dprint check and eslint on the touched files, all clean.

[Connor Peet (connor4312)]

thanks!