sparse-checkout: disable advice in 'disable'

When running 'git sparse-checkout disable' with the sparse index
enabled, Git is expected to expand the index into a full index. However,
it currently outputs the advice message saying that that is unexpected
and likely due to an issue with the working directory.

Disable this advice message when in this code path. Establish a pattern
for doing a similar removal in the future.

Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: derrickstolee

builtin/sparse-checkout.c

@@ -925,6 +925,11 @@ static int sparse_checkout_disable(int argc, const char **argv,
 			     builtin_sparse_checkout_disable_options,
 			     builtin_sparse_checkout_disable_usage, 0);
 
+	/*
+	 * Disable the advice message for expanding a sparse index, as we
+	 * are expecting to do that when disabling sparse-checkout.
+	 */
+	give_advice_on_expansion = 0;
 	repo_read_index(the_repository);
 
 	memset(&pl, 0, sizeof(pl));

sparse-index.c

@@ -19,9 +19,10 @@
  * advice for advice.sparseIndexExpanded when expanding a sparse index to a full
  * one. However, this is sometimes done on purpose, such as in the sparse-checkout
  * builtin, even when index.sparse=false. This may be disabled in
- * convert_to_sparse().
+ * convert_to_sparse() or by commands that know they will lead to a full
+ * expansion, but this message is not actionable.
  */
-static int give_advice_on_expansion = 1;
+int give_advice_on_expansion = 1;
 #define ADVICE_MSG \
 	"The sparse index is expanding to a full index, a slow operation.\n"   \
 	"Your working directory likely has contents that are outside of\n"     \

sparse-index.h

@@ -1,6 +1,13 @@
 #ifndef SPARSE_INDEX_H__
 #define SPARSE_INDEX_H__
 
+/*
+ * If performing an operation where the index is supposed to expand to a
+ * full index, then disable the advice message by setting this global to
+ * zero.
+ */
+extern int give_advice_on_expansion;
+
 struct index_state;
 #define SPARSE_INDEX_MEMORY_ONLY (1 << 0)
 int is_sparse_index_allowed(struct index_state *istate, int flags);

t/t1092-sparse-checkout-compatibility.sh

@@ -2342,7 +2342,10 @@ test_expect_success 'advice.sparseIndexExpanded' '
 	mkdir -p sparse-index/deep/deeper2/deepest &&
 	touch sparse-index/deep/deeper2/deepest/bogus &&
 	git -C sparse-index status 2>err &&
-	grep "The sparse index is expanding to a full index" err
+	grep "The sparse index is expanding to a full index" err &&
+
+	git -C sparse-index sparse-checkout disable 2>err &&
+	test_line_count = 0 err
 '
 
 test_done