Extract into variables: overlapping ranges not permitted

[Veykril]

fn expander_to_proc_macro(
    expander: proc_macro_api::ProcMacro,
    ignored_macros: &[Box<str>],
) -> ProcMacro {
    let name = From::from(expander.name());
    let kind = match expander.kind() {
        proc_macro_api::ProcMacroKind::CustomDerive => ProcMacroKind::CustomDerive,
        proc_macro_api::ProcMacroKind::FuncLike => ProcMacroKind::FuncLike,
        proc_macro_api::ProcMacroKind::Attr => ProcMacroKind::Attr,
    };
    ProcMacro {
        name,
        kind,
        expander: sync::Arc::new(Expander(expander)),
        disabled: $0ignored_macros.iter().any(|replace| **replace == name)$0,
    }
}

Invoking Extract into variables on that range here errors with overlapping ranges not permitted. I've been running into this quite frequently recently.

[Veykril]

@DropDemBits I think this might be due to 1e1761e, if you have the time to look into that that at some point would be nice :) (anyone else is welcome to as well of course)

[roife]

It works fine with latest master branch on my machine.

[Veykril]

This seems to be location sensitive 😖 if you place that concrete snippet over https://github.com/rust-lang/rust-analyzer/blame/47b4dd72730e1b3d475cee8361faf47b79b0f583/crates/load-cargo/src/lib.rs#L349-L361 it triggers the error, if you put that function somewhere else it doesn't necessarily happen

[DropDemBits]

Hmm, that feels like it has like something to do with snippet rendering, so I should look into that.

@rustbot claim

[DropDemBits]

I've managed to minimize it to this:

fn expander_to_proc_macro() -> ProcMacro {
    ProcMacro {
        disabled: $0false$0,
    }
}

struct ProcMacro {
    disabled: bool,
}

Which generates this SourceChange:

SourceChange {
    source_file_edits: {
        FileId(
            0,
        ): (
            TextEdit {
                indels: [
                    Indel {
                        insert: "let",
                        delete: 47..56,
                    },
                    Indel {
                        insert: "disabled = false;\n    ProcMacro {\n        disabled,\n    }",
                        delete: 57..89,
                    },
                ],
            },
            Some(
                SnippetEdit(
                    [
                        (
                            0,
                            51..51,
                        ),
                    ],
                ),
            ),
        ),
    },
    file_system_edits: [],
    is_snippet: true,
}

This is a problem for the current snippet rendering code since it doesn't account for differences between the final source range and the initial source range when determining the new range that an Indel covers, and therefore whether a snippet lands inside of an Indel or not.