tap: support fast clone

Closes Homebrew/homebrew#37592.
Closes Homebrew/homebrew#38268.

Signed-off-by: Xu Cheng <xucheng@me.com>

3 files changed, 11 insertions, 4 deletions

diff --git a/Library/Homebrew/cmd/tap.rb b/Library/Homebrew/cmd/tap.rb
index 34db5a9e4..5e0554dbb 100644
--- a/Library/Homebrew/cmd/tap.rb
+++ b/Library/Homebrew/cmd/tap.rb
@@ -20,7 +20,9 @@ module Homebrew
     tapd = HOMEBREW_LIBRARY/"Taps/#{user.downcase}/homebrew-#{repo.downcase}"
     return false if tapd.directory?
     ohai "Tapping #{repouser}/#{repo}"
-    abort unless system "git", "clone", "https://github.com/#{repouser}/homebrew-#{repo}", tapd.to_s
+    args = %W[clone https://github.com/#{repouser}/homebrew-#{repo} #{tapd}]
+    args << "--depth=1" unless ARGV.include?("--full")
+    safe_system "git", *args
 
     files = []
     tapd.find_formula { |file| files << file }
@@ -109,7 +111,7 @@ module Homebrew
     end
   end
 
-  def tap_args(tap_name=ARGV.first)
+  def tap_args(tap_name=ARGV.named.first)
     tap_name =~ HOMEBREW_TAP_ARGS_REGEX
     raise "Invalid tap name" unless $1 && $3
     [$1, $3]
diff --git a/Library/Homebrew/manpages/brew.1.md b/Library/Homebrew/manpages/brew.1.md
index c7a2206a4..d22373517 100644
--- a/Library/Homebrew/manpages/brew.1.md
+++ b/Library/Homebrew/manpages/brew.1.md
@@ -345,11 +345,13 @@ Note that these flags should only appear after a command.
   * `switch` <name> <version>:
     Symlink all of the specific <version> of <name>'s install to Homebrew prefix.
 
-  * `tap` [<tap>]:
+  * `tap` [--full] [<tap>]:
     Tap a new formula repository from GitHub, or list existing taps.
 
     <tap> is of the form <user>/<repo>, e.g. `brew tap homebrew/dupes`.
 
+    If `--full` is passed, a full clone will be used.
+
   * `tap --repair`:
     Ensure all tapped formulae are symlinked into Library/Formula and prune dead
     formulae from Library/Formula.
diff --git a/share/man/man1/brew.1 b/share/man/man1/brew.1
index 4997ce171..08c54d0cd 100644
--- a/share/man/man1/brew.1
+++ b/share/man/man1/brew.1
@@ -369,12 +369,15 @@ Instantiate a Homebrew build environment\. Uses our years\-battle\-hardened Home
 Symlink all of the specific \fIversion\fR of \fIname\fR\'s install to Homebrew prefix\.
 .
 .TP
-\fBtap\fR [\fItap\fR]
+\fBtap\fR [\-\-full] [\fItap\fR]
 Tap a new formula repository from GitHub, or list existing taps\.
 .
 .IP
 \fItap\fR is of the form \fIuser\fR/\fIrepo\fR, e\.g\. \fBbrew tap homebrew/dupes\fR\.
 .
+.IP
+If \fB\-\-full\fR is passed, a full clone will be used\.
+.
 .TP
 \fBtap \-\-repair\fR
 Ensure all tapped formulae are symlinked into Library/Formula and prune dead formulae from Library/Formula\.