Let CommandRegistry create Candidate for completion (fixes #1119)

console/src/main/java/org/jline/console/CommandRegistry.java

@@ -12,6 +12,7 @@
 import java.io.PrintStream;
 import java.util.*;
 
+import org.jline.reader.Candidate;
 import org.jline.reader.impl.completer.SystemCompleter;
 import org.jline.terminal.Terminal;
 
@@ -42,10 +43,22 @@ static SystemCompleter aggregateCompleters(CommandRegistry... commandRegistries)
      */
     static SystemCompleter compileCompleters(CommandRegistry... commandRegistries) {
         SystemCompleter out = aggregateCompleters(commandRegistries);
-        out.compile();
+        out.compile(s -> createCandidate(commandRegistries, s));
         return out;
     }
 
+    static Candidate createCandidate(CommandRegistry[] commandRegistries, String command) {
+        String group = null, desc = null;
+        for (CommandRegistry registry : commandRegistries) {
+            if (registry.hasCommand(command)) {
+                group = registry.name();
+                desc = registry.commandInfo(command).stream().findFirst().orElse(null);
+                break;
+            }
+        }
+        return new Candidate(command, command, group, desc, null, null, true);
+    }
+
     /**
      * Returns the name of this registry.
      * @return the name of the registry

console/src/main/java/org/jline/console/impl/SystemRegistryImpl.java

@@ -306,7 +306,7 @@ private SystemCompleter _compileCompleters() {
         }
         local.add(customSystemCompleter);
         out.add(local);
-        out.compile();
+        out.compile(s -> CommandRegistry.createCandidate(commandRegistries, s));
         return out;
     }
 

reader/src/main/java/org/jline/reader/impl/completer/SystemCompleter.java

@@ -9,6 +9,8 @@
 package org.jline.reader.impl.completer;
 
 import java.util.*;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import org.jline.reader.Candidate;
 import org.jline.reader.Completer;
@@ -24,6 +26,7 @@
 public class SystemCompleter implements Completer {
     private Map<String, List<Completer>> completers = new HashMap<>();
     private Map<String, String> aliasCommand = new HashMap<>();
+    private Map<String, String> descriptions = new HashMap<>();
     private StringsCompleter commands;
     private boolean compiled = false;
 
@@ -123,7 +126,7 @@ private Map<String, String> getAliases() {
         return aliasCommand;
     }
 
-    public void compile() {
+    public void compile(Function<String, Candidate> candidateBuilder) {
         if (compiled) {
             return;
         }
@@ -139,7 +142,7 @@ public void compile() {
         completers = compiledCompleters;
         Set<String> cmds = new HashSet<>(completers.keySet());
         cmds.addAll(aliasCommand.keySet());
-        commands = new StringsCompleter(cmds);
+        commands = new StringsCompleter(cmds.stream().map(candidateBuilder).collect(Collectors.toList()));
         compiled = true;
     }