[#1408] (WIP pending #1574) synopsis should respect order (if specified)

src/main/java/picocli/CommandLine.java

@@ -15340,8 +15340,11 @@ public String fullSynopsis() {
          */
         public String synopsis(int synopsisHeadingLength) {
             if (!empty(commandSpec.usageMessage().customSynopsis())) { return customSynopsis(); }
+            Comparator<OptionSpec> sortStrategy = true // #1574 TODO commandSpec.usageMessage().sortSynopsis()
+                ? createShortOptionArityAndNameComparator() // alphabetic sort
+                : createOrderComparatorIfNecessary(commandSpec.options()); // explicit sort
             return commandSpec.usageMessage().abbreviateSynopsis() ? abbreviatedSynopsis()
-                    : detailedSynopsis(synopsisHeadingLength, createShortOptionArityAndNameComparator(), true);
+                    : detailedSynopsis(synopsisHeadingLength, sortStrategy, true);
         }
 
         /** Generates a generic synopsis like {@code <command name> [OPTIONS] [PARAM1 [PARAM2]...]}, omitting parts

src/test/java/picocli/OrderedSynopsisTest.java

@@ -0,0 +1,51 @@
+package picocli;
+
+import org.junit.Ignore;
+import org.junit.Test;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Option;
+
+import static org.junit.Assert.*;
+
+// https://github.com/remkop/picocli/issues/1408
+public class OrderedSynopsisTest {
+
+    @Ignore("#1408")
+    @Test
+    public void testIssue1408() {
+        @Command(name = "myCommand",
+            mixinStandardHelpOptions = true,
+            description = "A command with explicitly ordered options.",
+            sortOptions = false)
+        class Example {
+            @Option(names = { "-d", "--option-d" }, order = -10, description = "Should be first")
+            private void setD(String value) {
+                this.d = value;
+            }
+            private String d;
+
+            @Option(names = { "-c", "--option-c" }, order = -9, description = "Should be second")
+            private void setC(String value) {
+                this.c = value;
+            }
+            private String c;
+
+            @Option(names = { "-b", "--option-b" }, order = -8, description = "Should be third")
+            private String b;
+
+            @Option(names = { "-a", "--option-a" }, order = -7, description = "Should be fourth")
+            private String a;
+        }
+        String actual = new CommandLine(new Example()).getUsageMessage(CommandLine.Help.Ansi.OFF);
+        String expected = String.format("" +
+            "Usage: myCommand [-hV] [-d=<d>] [-c=<c>] [-b=<b>] [-a=<a>]%n" +
+            "A command with explicitly ordered options.%n" +
+            "  -d, --option-d=<d>   Should be first%n" +
+            "  -c, --option-c=<c>   Should be second%n" +
+            "  -b, --option-b=<b>   Should be third%n" +
+            "  -a, --option-a=<a>   Should be fourth%n" +
+            "  -h, --help           Show this help message and exit.%n" +
+            "  -V, --version        Print version information and exit.%n");
+        assertEquals(expected, actual);
+    }
+}