From 2e5180d38b33710506ab76dcf93f802864b9ec0f Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 21 Jan 2020 10:07:34 +0100
Subject: [PATCH] strv: get rid of strv_clear()

Let's remove a function of questionnable utility.

strv_clear() frees the items of a string array, but not the array
itself. i.e. it half-drestructs a string array and makes it empty. This
is not too useful an operation since we almost never need to just do
that, we also want to free the whole thing. In fact, strv_clear() is
only used in one of our .c file, and there it appears like unnecessary
optimization, given that for each array with n elements it leaves the
number of free()s we need to at O(n) which is not really an optimization
at all (it goes from n+1 to n, that's all).

Prompted by the discussions on #14605
---
 src/basic/strv.c                   | 9 ++-------
 src/basic/strv.h                   | 2 --
 src/libsystemd/sd-hwdb/hwdb-util.c | 6 +++---
 3 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/basic/strv.c b/src/basic/strv.c
index 74d20a9a95..096cb4e5d4 100644
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -57,20 +57,15 @@ char *strv_find_startswith(char * const *l, const char *name) {
         return NULL;
 }
 
-void strv_clear(char **l) {
+char **strv_free(char **l) {
         char **k;
 
         if (!l)
-                return;
+                return NULL;
 
         for (k = l; *k; k++)
                 free(*k);
 
-        *l = NULL;
-}
-
-char **strv_free(char **l) {
-        strv_clear(l);
         return mfree(l);
 }
 
diff --git a/src/basic/strv.h b/src/basic/strv.h
index 85a49ab5c3..e7c2b1a604 100644
--- a/src/basic/strv.h
+++ b/src/basic/strv.h
@@ -25,8 +25,6 @@ char **strv_free_erase(char **l);
 DEFINE_TRIVIAL_CLEANUP_FUNC(char**, strv_free_erase);
 #define _cleanup_strv_free_erase_ _cleanup_(strv_free_erasep)
 
-void strv_clear(char **l);
-
 char **strv_copy(char * const *l);
 size_t strv_length(char * const *l) _pure_;
 
diff --git a/src/libsystemd/sd-hwdb/hwdb-util.c b/src/libsystemd/sd-hwdb/hwdb-util.c
index c83575c7c8..1a2da9c79b 100644
--- a/src/libsystemd/sd-hwdb/hwdb-util.c
+++ b/src/libsystemd/sd-hwdb/hwdb-util.c
@@ -543,7 +543,7 @@ static int import_file(struct trie *trie, const char *filename, uint16_t file_pr
                                            "Property expected, ignoring record with no properties");
                                 r = -EINVAL;
                                 state = HW_NONE;
-                                strv_clear(match_list);
+                                match_list = strv_free(match_list);
                                 break;
                         }
 
@@ -571,7 +571,7 @@ static int import_file(struct trie *trie, const char *filename, uint16_t file_pr
                         if (len == 0) {
                                 /* end of record */
                                 state = HW_NONE;
-                                strv_clear(match_list);
+                                match_list = strv_free(match_list);
                                 break;
                         }
 
@@ -580,7 +580,7 @@ static int import_file(struct trie *trie, const char *filename, uint16_t file_pr
                                            "Property or empty line expected, got \"%s\", ignoring record", line);
                                 r = -EINVAL;
                                 state = HW_NONE;
-                                strv_clear(match_list);
+                                match_list = strv_free(match_list);
                                 break;
                         }