fix: StringIndexOutOfBoundsException in presentation compiler's hasColon method #23498
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…gth before accessing characters Fixes scalameta/metals#7575"
tgodzik
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Jul 23, 2025
…lon method (scala#23498) This PR fixes a `StringIndexOutOfBoundsException` that could occur in the presentation compiler when checking for colons in override completions. ## Problem The `dotty.tools.pc.completions.OverrideCompletions.hasColon` method was accessing characters at specific indices without first verifying that the indices were within the text bounds. This could cause crashes when the span end positions were at or beyond the text length. ## Solution Added bounds checking before accessing characters: - For `TypeDef` cases: verify `td.rhs.span.end < text.length` before `text.charAt(td.rhs.span.end)` - For `Template` parent cases: filter to ensure `text.length > idx` before `text.charAt(idx)` ## Testing The existing test suite passes, and a new test case `no-new-line` was added to cover the edge case. [resolves scalameta/metals#7575](scalameta/metals#7575) [Cherry-picked 01447df]
tgodzik
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Jul 24, 2025
…lon method (scala#23498) This PR fixes a `StringIndexOutOfBoundsException` that could occur in the presentation compiler when checking for colons in override completions. ## Problem The `dotty.tools.pc.completions.OverrideCompletions.hasColon` method was accessing characters at specific indices without first verifying that the indices were within the text bounds. This could cause crashes when the span end positions were at or beyond the text length. ## Solution Added bounds checking before accessing characters: - For `TypeDef` cases: verify `td.rhs.span.end < text.length` before `text.charAt(td.rhs.span.end)` - For `Template` parent cases: filter to ensure `text.length > idx` before `text.charAt(idx)` ## Testing The existing test suite passes, and a new test case `no-new-line` was added to cover the edge case. [resolves scalameta/metals#7575](scalameta/metals#7575) [Cherry-picked 01447df]
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This PR fixes a
StringIndexOutOfBoundsExceptionthat could occur in the presentation compiler when checking for colons in override completions.Problem
The
dotty.tools.pc.completions.OverrideCompletions.hasColonmethod was accessing characters at specific indices without first verifying that the indices were within the text bounds. This could cause crashes when the span end positions were at or beyond the text length.Solution
Added bounds checking before accessing characters:
TypeDefcases: verifytd.rhs.span.end < text.lengthbeforetext.charAt(td.rhs.span.end)Templateparent cases: filter to ensuretext.length > idxbeforetext.charAt(idx)Testing
The existing test suite passes, and a new test case
no-new-linewas added to cover the edge case.resolves scalameta/metals#7575