diff --git a/builtin/remote.c b/builtin/remote.c
index 0324a5d48d..b44f580b8c 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -493,13 +493,13 @@ static int get_head_names(const struct ref *remote_refs, struct ref_states *stat
 {
 	struct ref *ref, *matches;
 	struct ref *fetch_map = NULL, **fetch_map_tail = &fetch_map;
-	struct refspec_item refspec;
-	char refspec_str[] = "refs/heads/*";
+	struct refspec_item refspec = {
+		.force = 0,
+		.pattern = 1,
+		.src = (char *) "refs/heads/*",
+		.dst = (char *) "refs/heads/*",
+	};
 
-	memset(&refspec, 0, sizeof(refspec));
-	refspec.force = 0;
-	refspec.pattern = 1;
-	refspec.src = refspec.dst = refspec_str;
 	get_fetch_map(remote_refs, &refspec, &fetch_map_tail, 0);
 	matches = guess_remote_head(find_ref_by_name(remote_refs, "HEAD"),
 				    fetch_map, 1);
@@ -508,7 +508,6 @@ static int get_head_names(const struct ref *remote_refs, struct ref_states *stat
 
 	free_refs(fetch_map);
 	free_refs(matches);
-
 	return 0;
 }
 
diff --git a/compat/basename.c b/compat/basename.c
index c3c9d65fac..5aa320306b 100644
--- a/compat/basename.c
+++ b/compat/basename.c
@@ -1,11 +1,6 @@
 #include "../git-compat-util.h"
 #include "../strbuf.h"
 
-/*
- * Both basename(3P) and dirname(3P) are mis-specified because they return a
- * non-constant pointer even though it is specified that they may return a
- * pointer to internal memory. This variable here is a result of that.
- */
 static char current_directory[] = ".";
 
 /* Adapted from libiberty's basename.c.  */
@@ -17,7 +12,13 @@ char *gitbasename (char *path)
 		skip_dos_drive_prefix(&path);
 
 	if (!path || !*path)
-		return current_directory;
+		/*
+		 * basename(3P) is mis-specified because it returns a
+		 * non-constant pointer even though it is specified to return a
+		 * pointer to internal memory at times. The cast is a result of
+		 * that.
+		 */
+		return (char *) "";
 
 	for (base = path; *path; path++) {
 		if (!is_dir_sep(*path))
@@ -40,12 +41,14 @@ char *gitdirname(char *path)
 	char *p = path, *slash = NULL, c;
 	int dos_drive_prefix;
 
-	/*
-	 * Same here, dirname(3P) is broken because it returns a non-constant
-	 * pointer that may point to internal memory.
-	 */
 	if (!p)
-		return current_directory;
+		/*
+		 * dirname(3P) is mis-specified because it returns a
+		 * non-constant pointer even though it is specified to return a
+		 * pointer to internal memory at times. The cast is a result of
+		 * that.
+		 */
+		return (char *) "";
 
 	if ((dos_drive_prefix = skip_dos_drive_prefix(&p)) && !*p)
 		goto dot;
diff --git a/compat/mingw.c b/compat/mingw.c
index 60f0986f76..d378cd04cb 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2257,7 +2257,6 @@ struct passwd *getpwuid(int uid)
 {
 	static unsigned initialized;
 	static char user_name[100];
-	static char unknown[] = "unknown";
 	static struct passwd *p;
 	wchar_t buf[100];
 	DWORD len;
@@ -2280,7 +2279,11 @@ struct passwd *getpwuid(int uid)
 	p->pw_name = user_name;
 	p->pw_gecos = get_extended_user_info(NameDisplay);
 	if (!p->pw_gecos)
-		p->pw_gecos = unknown;
+		/*
+		 * Data returned by getpwuid(3P) is treated as internal and
+		 * must never be written to or freed.
+		 */
+		p->pw_gecos = (char *) "unknown";
 	p->pw_dir = NULL;
 
 	initialized = 1;
diff --git a/diff.c b/diff.c
index 1439a5a01d..cecda216cf 100644
--- a/diff.c
+++ b/diff.c
@@ -7231,12 +7231,11 @@ size_t fill_textconv(struct repository *r,
 		     struct diff_filespec *df,
 		     char **outbuf)
 {
-	static char empty_str[] = "";
 	size_t size;
 
 	if (!driver) {
 		if (!DIFF_FILE_VALID(df)) {
-			*outbuf = empty_str;
+			*outbuf = (char *) "";
 			return 0;
 		}
 		if (diff_populate_filespec(r, df, NULL))
diff --git a/entry.c b/entry.c
index 2fc06ac90c..f291d8eee6 100644
--- a/entry.c
+++ b/entry.c
@@ -167,6 +167,11 @@ static int remove_available_paths(struct string_list_item *item, void *cb_data)
 	return !available;
 }
 
+static int string_is_not_null(struct string_list_item *item, void *data UNUSED)
+{
+	return !!item->string;
+}
+
 int finish_delayed_checkout(struct checkout *state, int show_progress)
 {
 	int errs = 0;
@@ -175,7 +180,6 @@ int finish_delayed_checkout(struct checkout *state, int show_progress)
 	struct string_list_item *filter, *path;
 	struct progress *progress = NULL;
 	struct delayed_checkout *dco = state->delayed_checkout;
-	char empty_str[] = "";
 
 	if (!state->delayed_checkout)
 		return errs;
@@ -190,7 +194,7 @@ int finish_delayed_checkout(struct checkout *state, int show_progress)
 			if (!async_query_available_blobs(filter->string, &available_paths)) {
 				/* Filter reported an error */
 				errs = 1;
-				filter->string = empty_str;
+				filter->string = NULL;
 				continue;
 			}
 			if (available_paths.nr <= 0) {
@@ -200,7 +204,7 @@ int finish_delayed_checkout(struct checkout *state, int show_progress)
 				 * filter from the list (see
 				 * "string_list_remove_empty_items" call below).
 				 */
-				filter->string = empty_str;
+				filter->string = NULL;
 				continue;
 			}
 
@@ -226,7 +230,7 @@ int finish_delayed_checkout(struct checkout *state, int show_progress)
 					 * Do not ask the filter for available blobs,
 					 * again, as the filter is likely buggy.
 					 */
-					filter->string = empty_str;
+					filter->string = NULL;
 					continue;
 				}
 				ce = index_file_exists(state->istate, path->string,
@@ -240,7 +244,8 @@ int finish_delayed_checkout(struct checkout *state, int show_progress)
 					errs = 1;
 			}
 		}
-		string_list_remove_empty_items(&dco->filters, 0);
+
+		filter_string_list(&dco->filters, 0, string_is_not_null, NULL);
 	}
 	stop_progress(&progress);
 	string_list_clear(&dco->filters, 0);
diff --git a/ident.c b/ident.c
index df7aa42802..caf41fb2a9 100644
--- a/ident.c
+++ b/ident.c
@@ -46,14 +46,9 @@ static struct passwd *xgetpwuid_self(int *is_bogus)
 	pw = getpwuid(getuid());
 	if (!pw) {
 		static struct passwd fallback;
-		static char fallback_name[] = "unknown";
+		fallback.pw_name = (char *) "unknown";
 #ifndef NO_GECOS_IN_PWENT
-		static char fallback_gcos[] = "Unknown";
-#endif
-
-		fallback.pw_name = fallback_name;
-#ifndef NO_GECOS_IN_PWENT
-		fallback.pw_gecos = fallback_gcos;
+		fallback.pw_gecos = (char *) "Unknown";
 #endif
 		pw = &fallback;
 		if (is_bogus)
diff --git a/line-log.c b/line-log.c
index 9a298209d0..67c80b39a0 100644
--- a/line-log.c
+++ b/line-log.c
@@ -1036,7 +1036,7 @@ static int process_diff_filepair(struct rev_info *rev,
 	struct range_set tmp;
 	struct diff_ranges diff;
 	mmfile_t file_parent, file_target;
-	char empty_str[] = "";
+	char *parent_data_to_free = NULL;
 
 	assert(pair->two->path);
 	while (rg) {
@@ -1061,7 +1061,7 @@ static int process_diff_filepair(struct rev_info *rev,
 		file_parent.ptr = pair->one->data;
 		file_parent.size = pair->one->size;
 	} else {
-		file_parent.ptr = empty_str;
+		file_parent.ptr = parent_data_to_free = xstrdup("");
 		file_parent.size = 0;
 	}
 
@@ -1080,6 +1080,7 @@ static int process_diff_filepair(struct rev_info *rev,
 
 	diff_ranges_release(&diff);
 
+	free(parent_data_to_free);
 	return ((*diff_out)->parent.nr > 0);
 }
 
diff --git a/object-file.c b/object-file.c
index 46ea00ac46..b5b5a59dc6 100644
--- a/object-file.c
+++ b/object-file.c
@@ -277,18 +277,17 @@ int hash_algo_by_length(int len)
 static struct cached_object {
 	struct object_id oid;
 	enum object_type type;
-	void *buf;
+	const void *buf;
 	unsigned long size;
 } *cached_objects;
 static int cached_object_nr, cached_object_alloc;
 
-static char empty_tree_buf[] = "";
 static struct cached_object empty_tree = {
 	.oid = {
 		.hash = EMPTY_TREE_SHA1_BIN_LITERAL,
 	},
 	.type = OBJ_TREE,
-	.buf = empty_tree_buf,
+	.buf = "",
 };
 
 static struct cached_object *find_cached_object(const struct object_id *oid)
@@ -1779,6 +1778,10 @@ int pretend_object_file(void *buf, unsigned long len, enum object_type type,
 			struct object_id *oid)
 {
 	struct cached_object *co;
+	char *co_buf;
+
+	co_buf = xmalloc(len);
+	memcpy(co_buf, buf, len);
 
 	hash_object_file(the_hash_algo, buf, len, type, oid);
 	if (repo_has_object_file_with_flags(the_repository, oid, OBJECT_INFO_QUICK | OBJECT_INFO_SKIP_FETCH_OBJECT) ||
@@ -1788,8 +1791,7 @@ int pretend_object_file(void *buf, unsigned long len, enum object_type type,
 	co = &cached_objects[cached_object_nr++];
 	co->size = len;
 	co->type = type;
-	co->buf = xmalloc(len);
-	memcpy(co->buf, buf, len);
+	co->buf = co_buf;
 	oidcpy(&co->oid, oid);
 	return 0;
 }
diff --git a/pretty.c b/pretty.c
index 1a0030b32a..1df9d635fb 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1583,10 +1583,9 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 		return 1;
 	case 'D':
 		{
-			char empty_str[] = "";
 			const struct decoration_options opts = {
-				.prefix = empty_str,
-				.suffix = empty_str,
+				.prefix = (char *) "",
+				.suffix = (char *) "",
 			};
 
 			format_decorations(sb, commit, c->auto_color, &opts);
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index 1908e74dea..e77faa2b9d 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1285,7 +1285,6 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 	struct strbuf errbuf = STRBUF_INIT;
 	size_t logs_nr = 0, logs_alloc = 0, i;
 	const char *committer_info;
-	char head[] = "HEAD";
 	int ret;
 
 	committer_info = git_committer_info(0);
@@ -1341,10 +1340,10 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 	 * old reference.
 	 */
 	refs[0] = old_ref;
-	refs[0].refname = (char *)arg->newname;
+	refs[0].refname = xstrdup(arg->newname);
 	refs[0].update_index = creation_ts;
 	if (arg->delete_old) {
-		refs[1].refname = (char *)arg->oldname;
+		refs[1].refname = xstrdup(arg->oldname);
 		refs[1].value_type = REFTABLE_REF_DELETION;
 		refs[1].update_index = deletion_ts;
 	}
@@ -1367,7 +1366,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 		ALLOC_GROW(logs, logs_nr + 1, logs_alloc);
 		memset(&logs[logs_nr], 0, sizeof(logs[logs_nr]));
 		fill_reftable_log_record(&logs[logs_nr], &committer_ident);
-		logs[logs_nr].refname = (char *)arg->newname;
+		logs[logs_nr].refname = xstrdup(arg->newname);
 		logs[logs_nr].update_index = deletion_ts;
 		logs[logs_nr].value.update.message =
 			xstrndup(arg->logmsg, arg->refs->write_options.block_size / 2);
@@ -1388,7 +1387,13 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 		if (append_head_reflog) {
 			ALLOC_GROW(logs, logs_nr + 1, logs_alloc);
 			logs[logs_nr] = logs[logs_nr - 1];
-			logs[logs_nr].refname = head;
+			logs[logs_nr].refname = xstrdup("HEAD");
+			logs[logs_nr].value.update.name =
+				xstrdup(logs[logs_nr].value.update.name);
+			logs[logs_nr].value.update.email =
+				xstrdup(logs[logs_nr].value.update.email);
+			logs[logs_nr].value.update.message =
+				xstrdup(logs[logs_nr].value.update.message);
 			logs_nr++;
 		}
 	}
@@ -1399,7 +1404,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 	ALLOC_GROW(logs, logs_nr + 1, logs_alloc);
 	memset(&logs[logs_nr], 0, sizeof(logs[logs_nr]));
 	fill_reftable_log_record(&logs[logs_nr], &committer_ident);
-	logs[logs_nr].refname = (char *)arg->newname;
+	logs[logs_nr].refname = xstrdup(arg->newname);
 	logs[logs_nr].update_index = creation_ts;
 	logs[logs_nr].value.update.message =
 		xstrndup(arg->logmsg, arg->refs->write_options.block_size / 2);
@@ -1431,7 +1436,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 		 */
 		ALLOC_GROW(logs, logs_nr + 1, logs_alloc);
 		logs[logs_nr] = old_log;
-		logs[logs_nr].refname = (char *)arg->newname;
+		logs[logs_nr].refname = xstrdup(arg->newname);
 		logs_nr++;
 
 		/*
@@ -1440,7 +1445,7 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 		if (arg->delete_old) {
 			ALLOC_GROW(logs, logs_nr + 1, logs_alloc);
 			memset(&logs[logs_nr], 0, sizeof(logs[logs_nr]));
-			logs[logs_nr].refname = (char *)arg->oldname;
+			logs[logs_nr].refname = xstrdup(arg->oldname);
 			logs[logs_nr].value_type = REFTABLE_LOG_DELETION;
 			logs[logs_nr].update_index = old_log.update_index;
 			logs_nr++;
@@ -1463,13 +1468,11 @@ static int write_copy_table(struct reftable_writer *writer, void *cb_data)
 	reftable_iterator_destroy(&it);
 	string_list_clear(&skip, 0);
 	strbuf_release(&errbuf);
-	for (i = 0; i < logs_nr; i++) {
-		if (logs[i].refname == head)
-			continue;
-		logs[i].refname = NULL;
+	for (i = 0; i < logs_nr; i++)
 		reftable_log_record_release(&logs[i]);
-	}
 	free(logs);
+	for (i = 0; i < ARRAY_SIZE(refs); i++)
+		reftable_ref_record_release(&refs[i]);
 	reftable_ref_record_release(&old_ref);
 	reftable_log_record_release(&old_log);
 	return ret;
diff --git a/reftable/basics.c b/reftable/basics.c
index fea711db7e..0058619ca6 100644
--- a/reftable/basics.c
+++ b/reftable/basics.c
@@ -67,9 +67,9 @@ void free_names(char **a)
 	reftable_free(a);
 }
 
-size_t names_length(char **names)
+size_t names_length(const char **names)
 {
-	char **p = names;
+	const char **p = names;
 	while (*p)
 		p++;
 	return p - names;
@@ -102,15 +102,12 @@ void parse_names(char *buf, int size, char ***namesp)
 	*namesp = names;
 }
 
-int names_equal(char **a, char **b)
+int names_equal(const char **a, const char **b)
 {
-	int i = 0;
-	for (; a[i] && b[i]; i++) {
-		if (strcmp(a[i], b[i])) {
+	size_t i = 0;
+	for (; a[i] && b[i]; i++)
+		if (strcmp(a[i], b[i]))
 			return 0;
-		}
-	}
-
 	return a[i] == b[i];
 }
 
diff --git a/reftable/basics.h b/reftable/basics.h
index 523ecd5307..c8fec68d4e 100644
--- a/reftable/basics.h
+++ b/reftable/basics.h
@@ -42,10 +42,10 @@ void free_names(char **a);
 void parse_names(char *buf, int size, char ***namesp);
 
 /* compares two NULL-terminated arrays of strings. */
-int names_equal(char **a, char **b);
+int names_equal(const char **a, const char **b);
 
 /* returns the array size of a NULL-terminated array of strings. */
-size_t names_length(char **names);
+size_t names_length(const char **names);
 
 /* Allocation routines; they invoke the functions set through
  * reftable_set_alloc() */
diff --git a/reftable/basics_test.c b/reftable/basics_test.c
index 23fab22eb1..13bc761817 100644
--- a/reftable/basics_test.c
+++ b/reftable/basics_test.c
@@ -58,8 +58,7 @@ static void test_binsearch(void)
 
 static void test_names_length(void)
 {
-	char a[] = "a", b[] = "b";
-	char *names[] = { a, b, NULL };
+	const char *names[] = { "a", "b", NULL };
 	EXPECT(names_length(names) == 2);
 }
 
diff --git a/reftable/block_test.c b/reftable/block_test.c
index d5967b214d..90aecd5a7c 100644
--- a/reftable/block_test.c
+++ b/reftable/block_test.c
@@ -19,7 +19,7 @@ license that can be found in the LICENSE file or at
 static void test_block_read_write(void)
 {
 	const int header_off = 21; /* random */
-	char *names[30], empty_str[] = "";
+	char *names[30];
 	const int N = ARRAY_SIZE(names);
 	const int block_size = 1024;
 	struct reftable_block block = { NULL };
@@ -42,7 +42,7 @@ static void test_block_read_write(void)
 	block_writer_init(&bw, BLOCK_TYPE_REF, block.data, block_size,
 			  header_off, hash_size(GIT_SHA1_FORMAT_ID));
 
-	rec.u.ref.refname = empty_str;
+	rec.u.ref.refname = (char *) "";
 	rec.u.ref.value_type = REFTABLE_REF_DELETION;
 	n = block_writer_add(&bw, &rec);
 	EXPECT(n == REFTABLE_API_ERROR);
diff --git a/reftable/merged_test.c b/reftable/merged_test.c
index fd5a065e42..6d1159d12d 100644
--- a/reftable/merged_test.c
+++ b/reftable/merged_test.c
@@ -123,15 +123,14 @@ static void readers_destroy(struct reftable_reader **readers, size_t n)
 
 static void test_merged_between(void)
 {
-	char a[] = "a", b[] = "b";
 	struct reftable_ref_record r1[] = { {
-		.refname = b,
+		.refname = (char *) "b",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_VAL1,
 		.value.val1 = { 1, 2, 3, 0 },
 	} };
 	struct reftable_ref_record r2[] = { {
-		.refname = a,
+		.refname = (char *) "a",
 		.update_index = 2,
 		.value_type = REFTABLE_REF_DELETION,
 	} };
@@ -164,41 +163,40 @@ static void test_merged_between(void)
 
 static void test_merged(void)
 {
-	char a[] = "a", b[] = "b", c[] = "c", d[] = "d";
 	struct reftable_ref_record r1[] = {
 		{
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 1,
 			.value_type = REFTABLE_REF_VAL1,
 			.value.val1 = { 1 },
 		},
 		{
-			.refname = b,
+			.refname = (char *) "b",
 			.update_index = 1,
 			.value_type = REFTABLE_REF_VAL1,
 			.value.val1 = { 1 },
 		},
 		{
-			.refname = c,
+			.refname = (char *) "c",
 			.update_index = 1,
 			.value_type = REFTABLE_REF_VAL1,
 			.value.val1 = { 1 },
 		}
 	};
 	struct reftable_ref_record r2[] = { {
-		.refname = a,
+		.refname = (char *) "a",
 		.update_index = 2,
 		.value_type = REFTABLE_REF_DELETION,
 	} };
 	struct reftable_ref_record r3[] = {
 		{
-			.refname = c,
+			.refname = (char *) "c",
 			.update_index = 3,
 			.value_type = REFTABLE_REF_VAL1,
 			.value.val1 = { 2 },
 		},
 		{
-			.refname = d,
+			.refname = (char *) "d",
 			.update_index = 3,
 			.value_type = REFTABLE_REF_VAL1,
 			.value.val1 = { 1 },
@@ -291,52 +289,48 @@ merged_table_from_log_records(struct reftable_log_record **logs,
 
 static void test_merged_logs(void)
 {
-	char a[] = "a";
-	char name[] = "jane doe", email[] = "jane@invalid";
-	char message1[] = "message1", message2[] = "message2";
-	char message3[] = "message3";
 	struct reftable_log_record r1[] = {
 		{
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 2,
 			.value_type = REFTABLE_LOG_UPDATE,
 			.value.update = {
 				.old_hash = { 2 },
 				/* deletion */
-				.name = name,
-				.email = email,
-				.message = message2,
+				.name = (char *) "jane doe",
+				.email = (char *) "jane@invalid",
+				.message = (char *) "message2",
 			}
 		},
 		{
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 1,
 			.value_type = REFTABLE_LOG_UPDATE,
 			.value.update = {
 				.old_hash = { 1 },
 				.new_hash = { 2 },
-				.name = name,
-				.email = email,
-				.message = message1,
+				.name = (char *) "jane doe",
+				.email = (char *) "jane@invalid",
+				.message = (char *) "message1",
 			}
 		},
 	};
 	struct reftable_log_record r2[] = {
 		{
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 3,
 			.value_type = REFTABLE_LOG_UPDATE,
 			.value.update = {
 				.new_hash = { 3 },
-				.name = name,
-				.email = email,
-				.message = message3,
+				.name = (char *) "jane doe",
+				.email = (char *) "jane@invalid",
+				.message = (char *) "message3",
 			}
 		},
 	};
 	struct reftable_log_record r3[] = {
 		{
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 2,
 			.value_type = REFTABLE_LOG_DELETION,
 		},
@@ -406,13 +400,13 @@ static void test_merged_logs(void)
 
 static void test_default_write_opts(void)
 {
-	char master[] = "master";
 	struct reftable_write_options opts = { 0 };
 	struct strbuf buf = STRBUF_INIT;
 	struct reftable_writer *w =
 		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+
 	struct reftable_ref_record rec = {
-		.refname = master,
+		.refname = (char *) "master",
 		.update_index = 1,
 	};
 	int err;
diff --git a/reftable/readwrite_test.c b/reftable/readwrite_test.c
index 064d693111..c55019232b 100644
--- a/reftable/readwrite_test.c
+++ b/reftable/readwrite_test.c
@@ -56,7 +56,6 @@ static void write_table(char ***names, struct strbuf *buf, int N,
 	int i = 0, n;
 	struct reftable_log_record log = { NULL };
 	const struct reftable_stats *stats = NULL;
-	char message[] = "message";
 
 	REFTABLE_CALLOC_ARRAY(*names, N + 1);
 
@@ -87,7 +86,7 @@ static void write_table(char ***names, struct strbuf *buf, int N,
 		log.update_index = update_index;
 		log.value_type = REFTABLE_LOG_UPDATE;
 		set_test_hash(log.value.update.new_hash, i);
-		log.value.update.message = message;
+		log.value.update.message = (char *) "message";
 
 		n = reftable_writer_add_log(w, &log);
 		EXPECT(n == 0);
@@ -112,28 +111,23 @@ static void write_table(char ***names, struct strbuf *buf, int N,
 
 static void test_log_buffer_size(void)
 {
-	char refname[] = "refs/heads/master";
-	char name[] = "Han-Wen Hienhuys";
-	char email[] = "hanwen@google.com";
-	char message[] = "commit: 9\n";
 	struct strbuf buf = STRBUF_INIT;
 	struct reftable_write_options opts = {
 		.block_size = 4096,
 	};
 	int err;
 	int i;
-	struct reftable_log_record log = {
-		.refname = refname,
-		.update_index = 0xa,
-		.value_type = REFTABLE_LOG_UPDATE,
-		.value.update = {
-			.name = name,
-			.email = email,
-			.tz_offset = 100,
-			.time = 0x5e430672,
-			.message = message,
-		},
-	};
+	struct reftable_log_record
+		log = { .refname = (char *) "refs/heads/master",
+			.update_index = 0xa,
+			.value_type = REFTABLE_LOG_UPDATE,
+			.value = { .update = {
+					   .name = (char *) "Han-Wen Nienhuys",
+					   .email = (char *) "hanwen@google.com",
+					   .tz_offset = 100,
+					   .time = 0x5e430672,
+					   .message = (char *) "commit: 9\n",
+				   } } };
 	struct reftable_writer *w =
 		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
 
@@ -155,9 +149,6 @@ static void test_log_buffer_size(void)
 
 static void test_log_overflow(void)
 {
-	char refname[] = "refs/heads/master";
-	char name[] = "Han-Wen Hienhuys";
-	char email[] = "hanwen@google.com";
 	struct strbuf buf = STRBUF_INIT;
 	char msg[256] = { 0 };
 	struct reftable_write_options opts = {
@@ -165,15 +156,15 @@ static void test_log_overflow(void)
 	};
 	int err;
 	struct reftable_log_record log = {
-		.refname = refname,
+		.refname = (char *) "refs/heads/master",
 		.update_index = 0xa,
 		.value_type = REFTABLE_LOG_UPDATE,
 		.value = {
 			.update = {
 				.old_hash = { 1 },
 				.new_hash = { 2 },
-				.name = name,
-				.email = email,
+				.name = (char *) "Han-Wen Nienhuys",
+				.email = (char *) "hanwen@google.com",
 				.tz_offset = 100,
 				.time = 0x5e430672,
 				.message = msg,
@@ -299,20 +290,17 @@ static void test_log_zlib_corruption(void)
 	struct reftable_writer *w =
 		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
 	const struct reftable_stats *stats = NULL;
-	char refname[] = "refname";
-	char name[] = "My Name";
-	char email[] = "myname@invalid";
 	char message[100] = { 0 };
 	int err, i, n;
 	struct reftable_log_record log = {
-		.refname = refname,
+		.refname = (char *) "refname",
 		.value_type = REFTABLE_LOG_UPDATE,
 		.value = {
 			.update = {
 				.new_hash = { 1 },
 				.old_hash = { 2 },
-				.name = name,
-				.email = email,
+				.name = (char *) "My Name",
+				.email = (char *) "myname@invalid",
 				.message = message,
 			},
 		},
@@ -739,9 +727,8 @@ static void test_write_empty_key(void)
 	struct strbuf buf = STRBUF_INIT;
 	struct reftable_writer *w =
 		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
-	char refname[] = "";
 	struct reftable_ref_record ref = {
-		.refname = refname,
+		.refname = (char *) "",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_DELETION,
 	};
@@ -763,21 +750,20 @@ static void test_write_key_order(void)
 	struct strbuf buf = STRBUF_INIT;
 	struct reftable_writer *w =
 		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
-	char a[] = "a", b[] = "b", target[] = "target";
 	struct reftable_ref_record refs[2] = {
 		{
-			.refname = b,
+			.refname = (char *) "b",
 			.update_index = 1,
 			.value_type = REFTABLE_REF_SYMREF,
 			.value = {
-				.symref = target,
+				.symref = (char *) "target",
 			},
 		}, {
-			.refname = a,
+			.refname = (char *) "a",
 			.update_index = 1,
 			.value_type = REFTABLE_REF_SYMREF,
 			.value = {
-				.symref = target,
+				.symref = (char *) "target",
 			},
 		}
 	};
diff --git a/reftable/stack.c b/reftable/stack.c
index a59ebe038d..09549c51c9 100644
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -204,7 +204,8 @@ static struct reftable_reader **stack_copy_readers(struct reftable_stack *st,
 	return cur;
 }
 
-static int reftable_stack_reload_once(struct reftable_stack *st, char **names,
+static int reftable_stack_reload_once(struct reftable_stack *st,
+				      const char **names,
 				      int reuse_open)
 {
 	size_t cur_len = !st->merged ? 0 : st->merged->stack_len;
@@ -222,7 +223,7 @@ static int reftable_stack_reload_once(struct reftable_stack *st, char **names,
 
 	while (*names) {
 		struct reftable_reader *rd = NULL;
-		char *name = *names++;
+		const char *name = *names++;
 
 		/* this is linear; we assume compaction keeps the number of
 		   tables under control so this is not quadratic. */
@@ -354,7 +355,7 @@ static int reftable_stack_reload_maybe_reuse(struct reftable_stack *st,
 				goto out;
 		}
 
-		err = reftable_stack_reload_once(st, names, reuse_open);
+		err = reftable_stack_reload_once(st, (const char **) names, reuse_open);
 		if (!err)
 			break;
 		if (err != REFTABLE_NOT_EXIST_ERROR)
@@ -368,7 +369,8 @@ static int reftable_stack_reload_maybe_reuse(struct reftable_stack *st,
 		err = read_lines(st->list_file, &names_after);
 		if (err < 0)
 			goto out;
-		if (names_equal(names_after, names)) {
+		if (names_equal((const char **) names_after,
+				(const char **) names)) {
 			err = REFTABLE_NOT_EXIST_ERROR;
 			goto out;
 		}
diff --git a/reftable/stack_test.c b/reftable/stack_test.c
index c6d88e6ea8..4abf92636d 100644
--- a/reftable/stack_test.c
+++ b/reftable/stack_test.c
@@ -116,14 +116,13 @@ static void test_parse_names(void)
 
 static void test_names_equal(void)
 {
-	char a[] = "a", b[] = "b", c[] = "c", d[] = "d";
-	char *abc[] = { a, b, c, NULL };
-	char *abd[] = { a, b, d, NULL };
-	char *ab[] = { a, b, NULL };
-
-	EXPECT(names_equal(abc, abc));
-	EXPECT(!names_equal(abc, abd));
-	EXPECT(!names_equal(abc, ab));
+	const char *a[] = { "a", "b", "c", NULL };
+	const char *b[] = { "a", "b", "d", NULL };
+	const char *c[] = { "a", "b", NULL };
+
+	EXPECT(names_equal(a, a));
+	EXPECT(!names_equal(a, b));
+	EXPECT(!names_equal(a, c));
 }
 
 static int write_test_ref(struct reftable_writer *wr, void *arg)
@@ -156,12 +155,11 @@ static void test_reftable_stack_add_one(void)
 	};
 	struct reftable_stack *st = NULL;
 	int err;
-	char head[] = "HEAD", master[] = "master";
 	struct reftable_ref_record ref = {
-		.refname = head,
+		.refname = (char *) "HEAD",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 	struct reftable_ref_record dest = { NULL };
 	struct stat stat_result = { 0 };
@@ -217,18 +215,17 @@ static void test_reftable_stack_uptodate(void)
 	char *dir = get_tmp_dir(__LINE__);
 
 	int err;
-	char head[] = "HEAD", branch2[] = "branch2", master[] = "master";
 	struct reftable_ref_record ref1 = {
-		.refname = head,
+		.refname = (char *) "HEAD",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 	struct reftable_ref_record ref2 = {
-		.refname = branch2,
+		.refname = (char *) "branch2",
 		.update_index = 2,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 
 
@@ -265,12 +262,12 @@ static void test_reftable_stack_transaction_api(void)
 	struct reftable_stack *st = NULL;
 	int err;
 	struct reftable_addition *add = NULL;
-	char head[] = "HEAD", master[] = "master";
+
 	struct reftable_ref_record ref = {
-		.refname = head,
+		.refname = (char *) "HEAD",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 	struct reftable_ref_record dest = { NULL };
 
@@ -313,11 +310,10 @@ static void test_reftable_stack_transaction_api_performs_auto_compaction(void)
 	EXPECT_ERR(err);
 
 	for (i = 0; i <= n; i++) {
-		char master[] = "master";
 		struct reftable_ref_record ref = {
 			.update_index = reftable_stack_next_update_index(st),
 			.value_type = REFTABLE_REF_SYMREF,
-			.value.symref = master,
+			.value.symref = (char *) "master",
 		};
 		char name[100];
 
@@ -359,9 +355,8 @@ static void test_reftable_stack_transaction_api_performs_auto_compaction(void)
 
 static void test_reftable_stack_auto_compaction_fails_gracefully(void)
 {
-	char master[] = "refs/meads/master";
 	struct reftable_ref_record ref = {
-		.refname = master,
+		.refname = (char *) "refs/heads/master",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_VAL1,
 		.value.val1 = {0x01},
@@ -409,21 +404,21 @@ static int write_error(struct reftable_writer *wr, void *arg)
 static void test_reftable_stack_update_index_check(void)
 {
 	char *dir = get_tmp_dir(__LINE__);
+
 	struct reftable_write_options cfg = { 0 };
 	struct reftable_stack *st = NULL;
 	int err;
-	char name1[] = "name1", name2[] = "name2", master[] = "master";
 	struct reftable_ref_record ref1 = {
-		.refname = name1,
+		.refname = (char *) "name1",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 	struct reftable_ref_record ref2 = {
-		.refname = name2,
+		.refname = (char *) "name2",
 		.update_index = 1,
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = master,
+		.value.symref = (char *) "master",
 	};
 
 	err = reftable_new_stack(&st, dir, cfg);
@@ -565,12 +560,8 @@ static void test_reftable_stack_log_normalize(void)
 	};
 	struct reftable_stack *st = NULL;
 	char *dir = get_tmp_dir(__LINE__);
-	char branch[] = "branch";
-	char onetwomessage[] = "one\ntwo";
-	char onemessage[] = "one";
-	char twomessage[] = "two\n";
 	struct reftable_log_record input = {
-		.refname = branch,
+		.refname = (char *) "branch",
 		.update_index = 1,
 		.value_type = REFTABLE_LOG_UPDATE,
 		.value = {
@@ -591,11 +582,11 @@ static void test_reftable_stack_log_normalize(void)
 	err = reftable_new_stack(&st, dir, cfg);
 	EXPECT_ERR(err);
 
-	input.value.update.message = onetwomessage;
+	input.value.update.message = (char *) "one\ntwo";
 	err = reftable_stack_add(st, &write_test_log, &arg);
 	EXPECT(err == REFTABLE_API_ERROR);
 
-	input.value.update.message = onemessage;
+	input.value.update.message = (char *) "one";
 	err = reftable_stack_add(st, &write_test_log, &arg);
 	EXPECT_ERR(err);
 
@@ -603,7 +594,7 @@ static void test_reftable_stack_log_normalize(void)
 	EXPECT_ERR(err);
 	EXPECT(0 == strcmp(dest.value.update.message, "one\n"));
 
-	input.value.update.message = twomessage;
+	input.value.update.message = (char *) "two\n";
 	arg.update_index = 2;
 	err = reftable_stack_add(st, &write_test_log, &arg);
 	EXPECT_ERR(err);
@@ -700,14 +691,15 @@ static void test_reftable_stack_tombstone(void)
 static void test_reftable_stack_hash_id(void)
 {
 	char *dir = get_tmp_dir(__LINE__);
+
 	struct reftable_write_options cfg = { 0 };
 	struct reftable_stack *st = NULL;
 	int err;
-	char master[] = "master", target[] = "target";
+
 	struct reftable_ref_record ref = {
-		.refname = master,
+		.refname = (char *) "master",
 		.value_type = REFTABLE_REF_SYMREF,
-		.value.symref = target,
+		.value.symref = (char *) "target",
 		.update_index = 1,
 	};
 	struct reftable_write_options cfg32 = { .hash_id = GIT_SHA256_FORMAT_ID };
@@ -882,12 +874,12 @@ static void test_reftable_stack_auto_compaction(void)
 	EXPECT_ERR(err);
 
 	for (i = 0; i < N; i++) {
-		char name[100], master[] = "master";
+		char name[100];
 		struct reftable_ref_record ref = {
 			.refname = name,
 			.update_index = reftable_stack_next_update_index(st),
 			.value_type = REFTABLE_REF_SYMREF,
-			.value.symref = master,
+			.value.symref = (char *) "master",
 		};
 		snprintf(name, sizeof(name), "branch%04d", i);
 
@@ -918,11 +910,10 @@ static void test_reftable_stack_add_performs_auto_compaction(void)
 	EXPECT_ERR(err);
 
 	for (i = 0; i <= n; i++) {
-		char master[] = "master";
 		struct reftable_ref_record ref = {
 			.update_index = reftable_stack_next_update_index(st),
 			.value_type = REFTABLE_REF_SYMREF,
-			.value.symref = master,
+			.value.symref = (char *) "master",
 		};
 
 		/*
@@ -968,12 +959,12 @@ static void test_reftable_stack_compaction_concurrent(void)
 	EXPECT_ERR(err);
 
 	for (i = 0; i < N; i++) {
-		char name[100], master[] = "master";
+		char name[100];
 		struct reftable_ref_record ref = {
 			.refname = name,
 			.update_index = reftable_stack_next_update_index(st1),
 			.value_type = REFTABLE_REF_SYMREF,
-			.value.symref = master,
+			.value.symref = (char *) "master",
 		};
 		snprintf(name, sizeof(name), "branch%04d", i);
 
@@ -1018,12 +1009,12 @@ static void test_reftable_stack_compaction_concurrent_clean(void)
 	EXPECT_ERR(err);
 
 	for (i = 0; i < N; i++) {
-		char name[100], master[] = "master";
+		char name[100];
 		struct reftable_ref_record ref = {
 			.refname = name,
 			.update_index = reftable_stack_next_update_index(st1),
 			.value_type = REFTABLE_REF_SYMREF,
-			.value.symref = master,
+			.value.symref = (char *) "master",
 		};
 		snprintf(name, sizeof(name), "branch%04d", i);
 
