[#1388] Fix subcommand aliases autocomplete regression

src/main/java/picocli/AutoComplete.java

@@ -560,7 +560,8 @@ private static void generateFunctionCallsToArrContains(StringBuilder buff,
             int count = functionCalls.size();
             CommandSpec spec = descriptor.commandLine.getCommandSpec();
             String full = spec.qualifiedName(" ");
-            String withoutTopLevelCommand = full.substring(spec.root().name().length() + 1);
+            String withoutTopLevelCommand = full.substring(spec.root().name().length() + 1,
+                    full.length() - spec.name().length()) + descriptor.commandName;
 
             functionCalls.add(format("  if CompWordsContainsArray \"${cmds%2$d[@]}\"; then %1$s; return $?; fi\n", descriptor.functionName, count));
             buff.append(      format("  local cmds%2$d=(%1$s)\n", withoutTopLevelCommand, count));

src/main/java/picocli/CommandLine.java

@@ -6412,7 +6412,7 @@ public CommandSpec addSubcommand(String name, CommandSpec subcommand) {
              */
             public CommandSpec addSubcommand(String name, CommandLine subCommandLine) {
                 CommandSpec subSpec = subCommandLine.getCommandSpec();
-                String actualName = validateSubcommandName(name, subSpec);
+                String actualName = validateSubcommandName(interpolator.interpolateCommandName(name), subSpec);
                 Tracer t = new Tracer();
                 if (t.isDebug()) {t.debug("Adding subcommand '%s' to '%s'%n", actualName, this.qualifiedName());}
                 String previousName = commands.getCaseSensitiveKey(actualName);
@@ -6422,7 +6422,7 @@ public CommandSpec addSubcommand(String name, CommandLine subCommandLine) {
                 subSpec.parent(this);
                 for (String alias : subSpec.aliases()) {
                     if (t.isDebug()) {t.debug("Adding alias '%s' for '%s'%n", (parent == null ? "" : parent.qualifiedName() + " ") + alias, this.qualifiedName());}
-                    previous = commands.put(alias, subCommandLine);
+                    previous = commands.put(interpolator.interpolate(alias), subCommandLine);
                     if (previous != null && previous != subCommandLine) { throw new DuplicateNameException("Alias '" + alias + "' for subcommand '" + actualName + "' is already used by another subcommand of '" + this.name() + "'"); }
                 }
                 subSpec.initCommandHierarchyWithResourceBundle(resourceBundleBaseName(), resourceBundle());

src/test/java/picocli/AutoCompleteTest.java

@@ -1896,4 +1896,35 @@ public void testIssue1352_SubcommandNameResourceBundle() throws FileNotFoundExce
         }
     }
 
+    @CommandLine.Command(name = "aliases", aliases = {"a"})
+    static class Issue1388AliasesCommand {}
+
+    @CommandLine.Command(name = "aliases-parent", subcommands = {Issue1388AliasesCommand.class})
+    static class Issue1388AliasesParentCommand {}
+
+    @Test
+    public void testIssue1388_AliasesCommand() throws FileNotFoundException {
+        File existingScript = new File("aliases-parent_completion");
+        if (existingScript.exists()) {
+            assertTrue(existingScript.delete());
+        }
+        try {
+            AutoComplete.main(Issue1388AliasesParentCommand.class.getName());
+
+            assertEquals("", systemErrRule.getLog());
+            assertEquals("", systemOutRule.getLog());
+
+            assertTrue("Expected file '" + existingScript.getAbsolutePath() + "' to exist",
+                    existingScript.exists());
+
+            Scanner scanner = new Scanner(existingScript);
+            scanner.useDelimiter("\\Z"); // end of file
+            String script = scanner.next();
+            scanner.close();
+            assertThat(script, containsString("local cmds0=(aliases)"));
+            assertThat(script, containsString("local cmds1=(a)"));
+        } finally {
+            existingScript.delete();
+        }
+    }
 }