On 11/19/2019 10:46 AM, SZEDER Gábor wrote:

On Mon, Oct 21, 2019 at 01:56:13PM +0000, Derrick Stolee via GitGitGadget wrote:

quoted

From: Derrick Stolee <redacted>

The 'git sparse-checkout set' subcommand takes a list of patterns
as arguments and writes them to the sparse-checkout file. Then, it
updates the working directory using 'git read-tree -mu HEAD'.

The 'set' subcommand will replace the entire contents of the
sparse-checkout file. The write_patterns_and_update() method is
extracted from cmd_sparse_checkout() to make it easier to implement
'add' and/or 'remove' subcommands in the future.

Yeah, an 'add' subcommand would be great, because 'set' throwing away
all the existing patterns can lead to some frustration:

I plan to extend this feature when this series lands.

Having said that, being forced to use 'git sparse-checkout set' and
specify all patterns at once does have its own benefits: I needed like
6 subdirectories to build that subset of a big project that I was
interested in, and now all the necessary patterns are saved in my Bash
history, and I will be able to easily dig out the complete command in
the future.  That wouldn't work with using the 'add' subcommand to add
one pattern at a time.

In general, this "set" command is created first because tools can interact
with it more easily than "add" and "remove". Users would probably prefer the
"add" and "remove" way to interact.
 

quoted

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index cb74715ca6..bf2dc55bb1 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh

@@ -96,4 +96,36 @@ test_expect_success 'clone --sparse' '
 	test_cmp expect dir
 '
 
+test_expect_success 'set enables config' '
+	git init empty-config &&
+	(
+		cd empty-config &&
+		test_commit test file &&
+		test_path_is_missing .git/config.worktree &&
+		test_must_fail git sparse-checkout set nothing &&

This command prints the same error message twice:

  + test_must_fail git sparse-checkout set nothing
  error: Sparse checkout leaves no entry on working directory
  error: Sparse checkout leaves no entry on working directory

At this commit, I do not see two identical lines, but instead the second
line says

	error: failed to update index with new sparse-checkout paths

(that "paths" should probably be "patterns")

Thanks,
-Stolee