From e70beb03229ed442633b955052ef38f2a90fa2f5 Mon Sep 17 00:00:00 2001
From: Tiago Lopes <tiago.maia.lopes@gmail.com>
Date: Sat, 11 Oct 2025 12:42:10 -0300
Subject: [PATCH] Suppress builtin -h,--help when command uses -h

Fixes part of the behavior described in issue 778 (https://github.com/apple/swift-argument-parser/issues/778).
---
 .../ArgumentParser/Usage/HelpGenerator.swift  | 14 ++++++++++-
 .../HelpGenerationTests.swift                 | 25 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/Sources/ArgumentParser/Usage/HelpGenerator.swift b/Sources/ArgumentParser/Usage/HelpGenerator.swift
index 4fc313042..0deb7ae85 100644
--- a/Sources/ArgumentParser/Usage/HelpGenerator.swift
+++ b/Sources/ArgumentParser/Usage/HelpGenerator.swift
@@ -519,7 +519,19 @@ extension BidirectionalCollection where Element == ParsableCommand.Type {
       })
     else { return ArgumentSet() }
     self.versionArgumentDefinition().map { arguments.append($0) }
-    self.helpArgumentDefinition().map { arguments.append($0) }
+    
+    let shouldAppendBuiltinHelp = !arguments
+      .flatMap(\.names)
+      .contains { name in
+        if case .short(let char, _) = name {
+          return char == "h"
+        }
+        return false
+      }
+    
+    if shouldAppendBuiltinHelp {
+      self.helpArgumentDefinition().map { arguments.append($0) }
+    }
 
     // To add when 'dump-help' is public API:
     // arguments.append(self.dumpHelpArgumentDefinition())
diff --git a/Tests/ArgumentParserUnitTests/HelpGenerationTests.swift b/Tests/ArgumentParserUnitTests/HelpGenerationTests.swift
index cc3973c71..3df0dbc7d 100644
--- a/Tests/ArgumentParserUnitTests/HelpGenerationTests.swift
+++ b/Tests/ArgumentParserUnitTests/HelpGenerationTests.swift
@@ -1493,3 +1493,28 @@ extension HelpGenerationTests {
     #endif
   }
 }
+
+extension HelpGenerationTests {
+  struct Issue778: ParsableCommand {
+    @Argument(help: "The phrase to repeat.")
+    var phrase: String
+    
+    @Option(name: .shortAndLong, help: "The name of the talking horse.")
+    var horse: String
+  }
+  
+  func testCommandWithShortOptionNameHDoesNotIncludeBuiltInHelp() {
+    AssertHelp(
+      .default, for: Issue778.self, columns: nil,
+      equals: """
+        USAGE: issue778 <phrase> --horse <horse>
+
+        ARGUMENTS:
+          <phrase>                The phrase to repeat.
+
+        OPTIONS:
+          -h, --horse <horse>     The name of the talking horse.
+        
+        """)
+  }
+}