AVDL nested imports cannot be resolved if path contains spaces

There is an issue when running the IDL tool if the IDL files have nested import statements, and the path includes a space (or probably any character that must be URL encoded). After the first level of import, the files can no longer be found. Consider the following three files in a avro bug directory:

root.avdl

protocol Root { 
    import idl "level1.avdl"; 
} 

level1.avdl

protocol Level1 {
    import idl "level2.avdl";
} 

level2.avdl

protocol Level2 {
} 

executing java -jar avro-tools-1.10.2.jar idl "avro bug/root.avdl" results in the expected
 

{
  "protocol" : "Root",
  "namespace" : null,
  "types" : [ ],
  "messages" : { }
} 

whereas java -jar avro-tools-1.11.1.jar idl "avro bug/root.avdl" causes an exception (the bug is also present in 1.11.0 with a slightly different stack trace)
  

Exception in thread "main" org.apache.avro.compiler.idl.ParseException: Error importing level2.avdl: java.io.FileNotFoundException: level2.avdl, at line 2, column 26
at org.apache.avro.compiler.idl.Idl.error(Idl.java:88)
at org.apache.avro.compiler.idl.Idl.ImportIdl(Idl.java:537)
at org.apache.avro.compiler.idl.Idl.ProtocolBody(Idl.java:411)
at org.apache.avro.compiler.idl.Idl.ProtocolDeclaration(Idl.java:286)
at org.apache.avro.compiler.idl.Idl.CompilationUnit(Idl.java:167)
at org.apache.avro.compiler.idl.Idl.ImportIdl(Idl.java:535)
at org.apache.avro.compiler.idl.Idl.ProtocolBody(Idl.java:411)
at org.apache.avro.compiler.idl.Idl.ProtocolDeclaration(Idl.java:286)
at org.apache.avro.compiler.idl.Idl.CompilationUnit(Idl.java:167)
at org.apache.avro.tool.IdlTool.run(IdlTool.java:61)
at org.apache.avro.tool.Main.run(Main.java:67)
at org.apache.avro.tool.Main.main(Main.java:56)

The same issue occurs if the files are located in "avro" but the current folder has spaces (ie, the absolute path to the avdl files contains spaces).

The bug appears to have been introduced in this commit https://github.com/apache/avro/commit/3fe5e306eaa43bdc06cef291321a8c04058a6be9#diff-376865a18691674de38817b4eea7e64c2c3848094a4730030c67f57f54f1028a in idl.jj lines 130 and 169.  The second time that line 130 is reached, it has an absolute path that is already URL-encoded.  In 1.10.2, the code new File(input.getPath()).getParentFile() returns a String like file:///home/user/avro%20bug/ whereas in 1.11.0 and later new File(input.getPath()).getParentFile().toURI() returns a String like file:///home/user/avro%2520bug - note that URL encoding has happened twice resulting in %2520 and there is no trailing slash. When resolved on line 169, this results in file:///home/user/level2.avdl instead of the correct file:///home/user/avro%20bug/level2.avdl.

This bug can be easily worked around by changing the location of the avdl files to one without spaces or other characters that must be URL encoded.