StringIndexOutOfBounds in help when command has too many (and long) aliases

[martlin2cz]

Hello,

I have a command with several aliases, and they are "long", like so:

@Command(name = "import-from-excel", 
          aliases = { "import-from-xls", "import-from-xlsx", "import-from-csv", "import-from-txt" },
          description = "Imports the data from various excel files (xls, xlsx, csv or even txt).")
public class ImportCommand implements Runnable {

    @Parameters(arity = "1..*")
    public List<File> files;
    
    @Override
    public void run() {
        System.out.println("ImportCommand.run()");    
    }

}

When I use it as a subcommand and trigger help on that supercommand (either by using the HelpCommand or via the usageHelp, picocli fails with following stack trace:

java.lang.IndexOutOfBoundsException: start 0, end -10, length 71
	at java.base/java.lang.AbstractStringBuilder.checkRange(AbstractStringBuilder.java:1802)
	at java.base/java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:680)
	at java.base/java.lang.StringBuilder.append(StringBuilder.java:218)
	at picocli.CommandLine$Help$Ansi$Text.getStyledChars(CommandLine.java:17646)
	at picocli.CommandLine$Help$TextTable.copy(CommandLine.java:16791)
	at picocli.CommandLine$Help$TextTable.copy(CommandLine.java:16780)
	at picocli.CommandLine$Help$TextTable.putValue(CommandLine.java:16742)
	at picocli.CommandLine$Help$TextTable.addRowValues(CommandLine.java:16674)
	at picocli.CommandLine$Help.commandList(CommandLine.java:15811)
	at picocli.CommandLine$Help.commandList(CommandLine.java:15788)
	at picocli.CommandLine$Model$UsageMessageSpec$15.render(CommandLine.java:7793)
	at picocli.CommandLine.usage(CommandLine.java:2673)
	at picocli.CommandLine.usage(CommandLine.java:2651)
	at picocli.CommandLine$HelpCommand.run(CommandLine.java:14755)
	at picocli.CommandLine.executeUserObject(CommandLine.java:1939)
	at picocli.CommandLine.executeHelpRequest(CommandLine.java:1929)
	at picocli.CommandLine.executeHelpRequest(CommandLine.java:1909)
	at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2176)
	at picocli.CommandLine.execute(CommandLine.java:2078)
	at cz.martlin.picoclifailuresample.MyPicocliMain.main(MyPicocliMain.java:14)

It all seems it's trying to fit all the alliases on one help line, but overflowing that line. If I remove the last alias, it outputs really narrow column with the description:

Usage: my [-h] [COMMAND]
  -h, --help
Commands:
  import-from-excel, import-from-xls, import-from-xlsx, import-from-csv  Imports
                                                                            the
                                                                           data
                                                                           from
                                                                           vario
                                                                           us
                                                                           excel

                                                                           files

                                                                           (xls,

                                                                           xlsx,
                                                                            csv
                                                                           or
                                                                           even
                                                                           txt).
  help                                                                   Display
                                                                           s
                                                                           help
                                                                           infor
                                                                           matio
                                                                           n
                                                                           about
                                                                            the
                                                                           speci
                                                                           fied
                                                                           comma
                                                                           nd

Could it be fixed please?

[remkop]

Nice catch! 👍
My time to work on picocli is extremely limited these days.
Will you be able to provide a pull request for this?

[martlin2cz]

Huh, it seems I won't be able to try to fix that.

There's even a question what should be a solution. Let it overflow? Wrap the line?

[remkop]

Picocli’s table component supports both of these options, so try both and see which result you like better.

[martlin2cz]

Huh, I'm sorry, I wasn't even able to manage my clone to build. It's not a high priority thing, it can wait , maybe a few months.

[remkop]

I have a fix, will commit shortly

Index: src/main/java/picocli/CommandLine.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/main/java/picocli/CommandLine.java b/src/main/java/picocli/CommandLine.java
--- a/src/main/java/picocli/CommandLine.java	(date 1674625453185)
+++ b/src/main/java/picocli/CommandLine.java	(date 1674625453185)
@@ -16340,7 +16340,8 @@
          * @since 4.4 */
         public String commandList(Map<String, Help> subcommands) {
             if (subcommands.isEmpty()) { return ""; }
-            int commandLength = maxLength(subcommands.keySet());
+            int maxCommandLength = width() * 2 / 3;
+            int commandLength = Math.min(maxLength(subcommands.keySet()), maxCommandLength);
             Help.TextTable textTable = Help.TextTable.forColumns(colorScheme().ansi(),
                     new Help.Column(commandLength + 2, 2, Help.Column.Overflow.SPAN),
                     new Help.Column(width() - (commandLength + 2), 2, Help.Column.Overflow.WRAP));

test
java/picocli/HelpSubCommandTest.java

    @Test
    public void testIssue1870StringIndexOutOfBounds() {
        @Command(name = "top", subcommands = ImportCommand.class) class Top { }
        String actual = usageString(new CommandLine(new Top()), Help.Ansi.OFF);
        String expected = String.format("" +
            "Usage: top [COMMAND]%n" +
            "Commands:%n" +
            "  import-from-excel, import-from-xls, import-from-xlsx, import-from-csv,%n" +
            "    import-from-txt%n" +
            "                                            Imports the data from various excel%n" +
            "                                              files (xls, xlsx, csv or even%n" +
            "                                              txt).%n");
        assertEquals(expected, actual);
    }