Dartc: conflict of a library prefix and a name in the importing library should produce a compile error

[DartBot]

This issue was originally filed by ms...@unipro.ru

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The specification in the section 12.2 says: "It is compile time error if the value of an actual argument to the prefix combinator denotes a name that is declared by the importing library."

So, the following code should produce a compile-time error:

import("some_library.dart", prefix: "prefix");

main() {
  int prefix;
  try {
    Expect.equals(1, prefix.foo);
  } catch(var e) {}
}

But dartc(r8186) produces a static warning: "Local variable 'prefix' is hiding 'LIBRARY_PREFIX prefix' at <unknown>::0:0"

[madsager]

Added Area-Analyzer, Triaged labels.

[danrubel]

Added this to the M1 milestone.

[scheglov]

Set owner to @scheglov.
Added Accepted label.

[scheglov]

https://chromiumcodereview.appspot.com/10538077

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Added Started label.

[scheglov]

https://code.google.com/p/dart/source/detail?r=8500

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Added Fixed label.

[DartBot]

This comment was originally written by rodion...@unipro.ru

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By the way, what about conflicts between prefix and a name imported from a second library? Spec doesn't seem to elaborate on that.

[bwilkerson]

I would assume that prefixes are added to the library scope like any other name and that a conflict with another imported name would be a compile time error.