[PATCH 2/3] dir: make clear_directory() free all relevant memory

["Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>]

From: Elijah Newren <newren@gmail.com>

The calling convention for the dir API is supposed to end with a call to
clear_directory() to free up no longer needed memory.  However,
clear_directory() didn't free dir->entries or dir->ignored.  I believe
this was oversight, but a number of callers noticed memory leaks and
started free'ing these, but often somewhat haphazardly (sometimes
freeing the entries in the arrays, and sometimes only free'ing the
arrays themselves).  This suggests the callers weren't trying to make
sure any possible memory used might be free'd, but just the memory they
noticed their usecase definitely had allocated.  This also caused the
extra memory deallocations to be duplicated in many places.

Fix this mess by moving all the duplicated free'ing logic into
clear_directory().

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 builtin/clean.c |  6 +-----
 builtin/stash.c |  3 ---
 dir.c           | 12 ++++++++----
 dir.h           |  2 +-
 wt-status.c     |  4 ----
 5 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/builtin/clean.c b/builtin/clean.c
index 5a9c29a558..4ffe00dd7f 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -1021,11 +1021,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		string_list_append(&del_list, rel);
 	}
 
-	for (i = 0; i < dir.nr; i++)
-		free(dir.entries[i]);
-
-	for (i = 0; i < dir.ignored_nr; i++)
-		free(dir.ignored[i]);
+	clear_directory(&dir);
 
 	if (interactive && del_list.nr > 0)
 		interactive_main_loop();
diff --git a/builtin/stash.c b/builtin/stash.c
index 10d87630cd..da48533d49 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -875,11 +875,8 @@ static int get_untracked_files(const struct pathspec *ps, int include_untracked,
 		strbuf_addstr(untracked_files, ent->name);
 		/* NUL-terminate: will be fed to update-index -z */
 		strbuf_addch(untracked_files, '\0');
-		free(ent);
 	}
 
-	free(dir.entries);
-	free(dir.ignored);
 	clear_directory(&dir);
 	return found;
 }
diff --git a/dir.c b/dir.c
index 08df469bf7..b136c037d9 100644
--- a/dir.c
+++ b/dir.c
@@ -3012,10 +3012,7 @@ int remove_path(const char *name)
 	return 0;
 }
 
-/*
- * Frees memory within dir which was allocated for exclude lists and
- * the exclude_stack.  Does not free dir itself.
- */
+/* Frees memory within dir which was allocated.  Does not free dir itself. */
 void clear_directory(struct dir_struct *dir)
 {
 	int i, j;
@@ -3034,6 +3031,13 @@ void clear_directory(struct dir_struct *dir)
 		free(group->pl);
 	}
 
+	for (i = 0; i < dir->ignored_nr; i++)
+		free(dir->ignored[i]);
+	for (i = 0; i < dir->nr; i++)
+		free(dir->entries[i]);
+	free(dir->ignored);
+	free(dir->entries);
+
 	stk = dir->exclude_stack;
 	while (stk) {
 		struct exclude_stack *prev = stk->prev;
diff --git a/dir.h b/dir.h
index 5855c065a6..7d76d0644f 100644
--- a/dir.h
+++ b/dir.h
@@ -36,7 +36,7 @@
  *
  * - Use `dir.entries[]`.
  *
- * - Call `clear_directory()` when none of the contained elements are no longer in use.
+ * - Call `clear_directory()` when the contained elements are no longer in use.
  *
  */
 
diff --git a/wt-status.c b/wt-status.c
index d75399085d..c00ea3e06a 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -724,18 +724,14 @@ static void wt_status_collect_untracked(struct wt_status *s)
 		struct dir_entry *ent = dir.entries[i];
 		if (index_name_is_other(istate, ent->name, ent->len))
 			string_list_insert(&s->untracked, ent->name);
-		free(ent);
 	}
 
 	for (i = 0; i < dir.ignored_nr; i++) {
 		struct dir_entry *ent = dir.ignored[i];
 		if (index_name_is_other(istate, ent->name, ent->len))
 			string_list_insert(&s->ignored, ent->name);
-		free(ent);
 	}
 
-	free(dir.entries);
-	free(dir.ignored);
 	clear_directory(&dir);
 
 	if (advice_status_u_option)
-- 
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