[PATCH 1/2] string_list API users + cocci: use string_list_init_dup()

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Add a coccinelle rule to detect a particular misuse of the "struct
string_list" API. We have the *_INIT macros, but this code assumed
that a zero'd out "struct string_list" with a "strdup_string" set
would be the same as string_list_init_dup().

That assumption happens to be right, but let's instead use the helper
functions introduced in 183113a5ca9 (string_list: Add STRING_LIST_INIT
macro and make use of it., 2010-07-04).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 contrib/coccinelle/string_list.cocci     | 8 ++++++++
 contrib/coccinelle/tests/string_list.c   | 7 +++++++
 contrib/coccinelle/tests/string_list.res | 7 +++++++
 refs.c                                   | 4 ++--
 resolve-undo.c                           | 8 ++++----
 revision.c                               | 4 ++--
 6 files changed, 30 insertions(+), 8 deletions(-)
 create mode 100644 contrib/coccinelle/string_list.cocci
 create mode 100644 contrib/coccinelle/tests/string_list.c
 create mode 100644 contrib/coccinelle/tests/string_list.res

diff --git a/contrib/coccinelle/string_list.cocci b/contrib/coccinelle/string_list.cocci
new file mode 100644
index 00000000000..5d285d5732c
--- /dev/null
+++ b/contrib/coccinelle/string_list.cocci
@@ -0,0 +1,8 @@
+@@
+struct string_list *P;
+@@
+- CALLOC_ARRAY(P, 1);
++ ALLOC_ARRAY(P, 1);
+... when != P
+- (P)->strdup_strings = 1;
++ string_list_init_dup(P);
diff --git a/contrib/coccinelle/tests/string_list.c b/contrib/coccinelle/tests/string_list.c
new file mode 100644
index 00000000000..e77822b7682
--- /dev/null
+++ b/contrib/coccinelle/tests/string_list.c
@@ -0,0 +1,7 @@
+int init(void)
+{
+	struct string_list *list;
+
+	CALLOC_ARRAY(list, 1);
+	list->strdup_strings = 1;
+}
diff --git a/contrib/coccinelle/tests/string_list.res b/contrib/coccinelle/tests/string_list.res
new file mode 100644
index 00000000000..7e666f5bf48
--- /dev/null
+++ b/contrib/coccinelle/tests/string_list.res
@@ -0,0 +1,7 @@
+int init(void)
+{
+	struct string_list *list;
+
+	ALLOC_ARRAY(list, 1);
+	string_list_init_dup(list);
+}
diff --git a/refs.c b/refs.c
index 90bcb271687..83151a42b3a 100644
--- a/refs.c
+++ b/refs.c
@@ -1313,8 +1313,8 @@ int parse_hide_refs_config(const char *var, const char *value, const char *secti
 		while (len && ref[len - 1] == '/')
 			ref[--len] = '\0';
 		if (!hide_refs) {
-			CALLOC_ARRAY(hide_refs, 1);
-			hide_refs->strdup_strings = 1;
+			ALLOC_ARRAY(hide_refs, 1);
+			string_list_init_dup(hide_refs);
 		}
 		string_list_append(hide_refs, ref);
 	}
diff --git a/resolve-undo.c b/resolve-undo.c
index e81096e2d45..e66b8306fe0 100644
--- a/resolve-undo.c
+++ b/resolve-undo.c
@@ -15,8 +15,8 @@ void record_resolve_undo(struct index_state *istate, struct cache_entry *ce)
 		return;
 
 	if (!istate->resolve_undo) {
-		CALLOC_ARRAY(resolve_undo, 1);
-		resolve_undo->strdup_strings = 1;
+		ALLOC_ARRAY(resolve_undo, 1);
+		string_list_init_dup(resolve_undo);
 		istate->resolve_undo = resolve_undo;
 	}
 	resolve_undo = istate->resolve_undo;
@@ -57,8 +57,8 @@ struct string_list *resolve_undo_read(const char *data, unsigned long size)
 	int i;
 	const unsigned rawsz = the_hash_algo->rawsz;
 
-	CALLOC_ARRAY(resolve_undo, 1);
-	resolve_undo->strdup_strings = 1;
+	ALLOC_ARRAY(resolve_undo, 1);
+	string_list_init_dup(resolve_undo);
 
 	while (size) {
 		struct string_list_item *lost;
diff --git a/revision.c b/revision.c
index 0c6e26cd9c8..e44af92cacc 100644
--- a/revision.c
+++ b/revision.c
@@ -1578,8 +1578,8 @@ void clear_ref_exclusion(struct string_list **ref_excludes_p)
 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
 {
 	if (!*ref_excludes_p) {
-		CALLOC_ARRAY(*ref_excludes_p, 1);
-		(*ref_excludes_p)->strdup_strings = 1;
+		ALLOC_ARRAY(*ref_excludes_p, 1);
+		string_list_init_dup(*ref_excludes_p);
 	}
 	string_list_append(*ref_excludes_p, exclude);
 }
-- 
2.37.1.1095.g64a1e8362fd