help: support `#:` help in external commands.

Fixes https://github.com/Homebrew/homebrew-test-bot/issues/3

1 files changed, 3 insertions, 1 deletions

diff --git a/Library/Homebrew/cmd/help.rb b/Library/Homebrew/cmd/help.rb
index 2a814b90b..200e68738 100644
--- a/Library/Homebrew/cmd/help.rb
+++ b/Library/Homebrew/cmd/help.rb
@@ -39,6 +39,8 @@ module Homebrew
     if cmd
       cmd = HOMEBREW_INTERNAL_COMMAND_ALIASES.fetch(cmd, cmd)
       path = Commands.path(cmd)
+      path ||= which("brew-#{cmd}")
+      path ||= which("brew-#{cmd}.rb")
     end
 
     # Display command-specific (or generic) help in response to `UsageError`.
@@ -61,7 +63,7 @@ module Homebrew
       exit 0
     end
 
-    # Resume execution in `brew.rb` for external/unknown commands.
+    # Resume execution in `brew.rb` for unknown commands.
     return if path.nil?
 
     # Display help for internal command (or generic help if undocumented).