11 files changed, 53 insertions, 59 deletions
diff --git a/source/cgit.c b/source/cgit.c
index 8dc90e6..2ef4cf1 100644
--- a/source/cgit.c
+++ b/source/cgit.c
@@ -1010,7 +1010,7 @@ static char *guess_defbranch(void)
 
 	ref = refs_resolve_ref_unsafe(get_main_ref_store(the_repository), "HEAD", 0, &oid, NULL);
 	if (!ref || !skip_prefix(ref, "refs/heads/", &refname))
-		return "master";
+		return xstrdup("master");
 	return xstrdup(refname);
 }
 
diff --git a/source/cgit.h b/source/cgit.h
index 30f97c5..5b92632 100644
--- a/source/cgit.h
+++ b/source/cgit.h
@@ -84,7 +84,7 @@ struct cgit_repo {
 	char *defbranch;
 	char *module_link;
 	struct string_list readme;
-	char *section;
+	const char *section;
 	char *clone_url;
 	char *logo;
 	char *logo_link;
@@ -166,7 +166,7 @@ struct cgit_query {
 	int has_difftype;
 	char *raw;
 	char *repo;
-	char *page;
+	const char *page;
 	char *search;
 	char *grep;
 	char *head;
@@ -188,28 +188,28 @@ struct cgit_query {
 };
 
 struct cgit_config {
-	char *agefile;
-	char *cache_root;
+	const char *agefile;
+	const char *cache_root;
 	char *clone_prefix;
 	char *clone_url;
-	char *favicon;
+	const char *favicon;
 	char *footer;
 	char *head_include;
 	char *header;
-	char *logo;
+	const char *logo;
 	char *logo_link;
 	char *mimetype_file;
 	char *module_link;
 	char *project_list;
 	struct string_list readme;
 	struct string_list css;
-	char *robots;
-	char *root_title;
-	char *root_desc;
+	const char *robots;
+	const char *root_title;
+	const char *root_desc;
 	char *root_readme;
-	char *script_name;
-	char *section;
-	char *repository_sort;
+	const char *script_name;
+	const char *section;
+	const char *repository_sort;
 	// Always ends with a slash.
 	char *virtual_root;
 	char *strict_export;
diff --git a/source/filter.c b/source/filter.c
index 6e16537..3ffd077 100644
--- a/source/filter.c
+++ b/source/filter.c
@@ -47,7 +47,8 @@ static int open_exec_filter(struct cgit_filter *base, va_list ap)
 		// cgit ignores SIGPIPE and the disposition survives exec, so a
 		// filter that writes to a closed pipe would otherwise carry on.
 		signal(SIGPIPE, SIG_DFL);
-		execvp(filter->cmd, filter->argv);
+		// execvp leaves argv alone, but its prototype predates const.
+		execvp(filter->cmd, (char *const *)filter->argv);
 		// The child shares the parent's page buffer, cache lock and exit
 		// handlers, so it must not die through them.
 		fprintf(stderr, "[cgit] Unable to exec filter %s: %s\n", filter->cmd, strerror(errno));
@@ -95,7 +96,7 @@ static void cleanup_exec_filter(struct cgit_filter *base)
 
 	free(filter->argv);
 	filter->argv = NULL;
-	free(filter->cmd);
+	free((char *)filter->cmd);
 	filter->cmd = NULL;
 }
 
@@ -116,7 +117,7 @@ static struct cgit_filter *new_exec_filter(const char *cmd, int argument_count)
 	return &filter->base;
 }
 
-void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **argv)
+void cgit_exec_filter_init(struct cgit_exec_filter *filter, const char *cmd, const char **argv)
 {
 	memset(filter, 0, sizeof(*filter));
 	filter->base.open = open_exec_filter;
diff --git a/source/filter.h b/source/filter.h
index 70fa4ff..2c8e7b7 100644
--- a/source/filter.h
+++ b/source/filter.h
@@ -26,16 +26,16 @@ struct cgit_filter {
 
 struct cgit_exec_filter {
 	struct cgit_filter base;
-	char *cmd;
-	char **argv;
+	const char *cmd;
+	const char **argv;
 	int old_stdout;
 	int pid;
 };
 
 extern struct cgit_filter *cgit_new_filter(const char *cmd,
 					   filter_type filtertype);
-extern void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd,
-				  char **argv);
+extern void cgit_exec_filter_init(struct cgit_exec_filter *filter, const char *cmd,
+				  const char **argv);
 
 /*
  * Redirect stdout into the filter and pass it the variadic arguments its type
diff --git a/source/shared.c b/source/shared.c
index a5c54ee..a6a5106 100644
--- a/source/shared.c
+++ b/source/shared.c
@@ -24,7 +24,7 @@ typedef struct {
 
 struct cgit_repolist cgit_repolist;
 struct cgit_context ctx;
-char *cgit_default_repo_desc = "[no description]";
+char cgit_default_repo_desc[] = "[no description]";
 
 // A diff line that arrived in pieces and is still waiting for its end, see
 // emit_line.
diff --git a/source/shared.h b/source/shared.h
index 13932c8..129cfb7 100644
--- a/source/shared.h
+++ b/source/shared.h
@@ -11,7 +11,7 @@
 
 #include "cgit.h"
 
-extern char *cgit_default_repo_desc;
+extern char cgit_default_repo_desc[];
 
 typedef void (*filepair_fn)(struct diff_filepair *pair);
 typedef void (*linediff_fn)(char *line, int len);
diff --git a/source/ui-diff.c b/source/ui-diff.c
index a5202b5..805733a 100644
--- a/source/ui-diff.c
+++ b/source/ui-diff.c
@@ -227,8 +227,8 @@ static char *abbrev_oid(const struct object_id *oid)
 	return xstrdup(repo_find_unique_abbrev(the_repository, oid, DEFAULT_ABBREV));
 }
 
-static void print_file_header(const struct object_id *old_oid, char *old_path, unsigned old_mode,
-	const struct object_id *new_oid, char *new_path, unsigned new_mode)
+static void print_file_header(const struct object_id *old_oid, const char *old_path, unsigned old_mode,
+	const struct object_id *new_oid, const char *new_path, unsigned new_mode)
 {
 	char *old_abbrev, *new_abbrev;
 	int subproject;
diff --git a/source/ui-plain.c b/source/ui-plain.c
index 6d02051..2463cfc 100644
--- a/source/ui-plain.c
+++ b/source/ui-plain.c
@@ -234,7 +234,7 @@ void cgit_print_plain(void)
 	if (!path_items.match) {
 		// The walk is never handed an entry for the top of the tree
 		// itself, so the listing it would have opened is opened here.
-		path_items.match = "";
+		paths.nr = 0;
 		walk.dir_len = -1;
 		print_dir("", 0, "");
 		walk.response = RESPONSE_LISTING;
diff --git a/source/ui-repolist.c b/source/ui-repolist.c
index 6dcc976..1394048 100644
--- a/source/ui-repolist.c
+++ b/source/ui-repolist.c
@@ -266,7 +266,7 @@ static void print_repo_row(const char *currenturl, int sublevel)
 static void print_pager(int total, int pagelen, char *search, char *sort)
 {
 	int i, ofs;
-	char *class;
+	const char *class;
 
 	html("<nav class='pager' aria-label='Pager'><ul>\n");
 	for (i = 0, ofs = 0; ofs < total; i++, ofs = i * pagelen) {
@@ -375,7 +375,7 @@ static const struct sort_column sort_columns[] = {
 	{NULL, NULL}
 };
 
-static int sort_repolist(char *field)
+static int sort_repolist(const char *field)
 {
 	const struct sort_column *column;
 
@@ -392,7 +392,7 @@ static int sort_repolist(char *field)
 
 void cgit_print_repolist(void)
 {
-	char *last_section = NULL;
+	const char *last_section = NULL;
 	char *currenturl;
 	int columns = BASE_COLUMNS;
 	int column_sorted = 0;
@@ -423,7 +423,7 @@ void cgit_print_repolist(void)
 	currenturl = cgit_currenturl();
 	html("<table class='list repolist' aria-label='Repositories'>\n");
 	for (i = 0; i < cgit_repolist.count; i++) {
-		char *section;
+		const char *section;
 
 		ctx.repo = &cgit_repolist.repos[i];
 		if (!is_visible(ctx.repo))
diff --git a/source/ui-shared.c b/source/ui-shared.c
index e5afb2e..b88edec 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -343,36 +343,26 @@ static void print_rel_vcs_link(const char *url)
 	html(" Git repository'>\n");
 }
 
-static int emit_css_link(struct string_list_item *item, void *fallback)
+static void emit_css_link(const char *href)
 {
 	// An empty css entry is how a site turns the stylesheet off.
-	if (item && *item->string == '\0')
-		return 0;
+	if (!*href)
+		return;
 
 	html("<link rel='stylesheet' href='");
-	if (item)
-		html_attr(item->string);
-	else
-		html_attr((const char *)fallback);
+	html_attr(href);
 	html("'>\n");
-
-	return 0;
 }
 
-static int emit_js_link(struct string_list_item *item, void *fallback)
+static void emit_js_link(const char *src)
 {
 	// An empty js entry is how a site turns the script off.
-	if (item && *item->string == '\0')
-		return 0;
+	if (!*src)
+		return;
 
 	html("<script src='");
-	if (item)
-		html_attr(item->string);
-	else
-		html_attr((const char *)fallback);
+	html_attr(src);
 	html("'></script>\n");
-
-	return 0;
 }
 
 static void add_clone_urls(void (*fn)(const char *), char *urls, char *suffix)
@@ -1495,6 +1485,7 @@ void cgit_redirect(const char *url, const char *query, bool permanent)
 void cgit_print_docstart(void)
 {
 	const struct object_id *pinned;
+	struct string_list_item *item;
 	char *host = cgit_hosturl();
 
 	if (ctx.cfg.embedded) {
@@ -1538,15 +1529,17 @@ void cgit_print_docstart(void)
 		html("'>\n");
 	}
 
-	if (ctx.cfg.css.items)
-		for_each_string_list(&ctx.cfg.css, emit_css_link, NULL);
+	if (ctx.cfg.css.nr)
+		for_each_string_list_item(item, &ctx.cfg.css)
+			emit_css_link(item->string);
 	else
-		emit_css_link(NULL, "/cgit.css");
+		emit_css_link("/cgit.css");
 
-	if (ctx.cfg.js.items)
-		for_each_string_list(&ctx.cfg.js, emit_js_link, NULL);
+	if (ctx.cfg.js.nr)
+		for_each_string_list_item(item, &ctx.cfg.js)
+			emit_js_link(item->string);
 	else
-		emit_js_link(NULL, "/cgit.js");
+		emit_js_link("/cgit.js");
 
 	if (ctx.cfg.favicon && *ctx.cfg.favicon) {
 		html("<link rel='icon' href='");
diff --git a/source/ui-snapshot.c b/source/ui-snapshot.c
index 348fd9c..24d1268 100644
--- a/source/ui-snapshot.c
+++ b/source/ui-snapshot.c
@@ -87,7 +87,7 @@ static int program_on_path(const char *program)
 	return found;
 }
 
-static int write_compressed_tar_archive(const char *hex, const char *prefix, char *argv[])
+static int write_compressed_tar_archive(const char *hex, const char *prefix, const char *argv[])
 {
 	struct cgit_exec_filter filter;
 	int result;
@@ -101,28 +101,28 @@ static int write_compressed_tar_archive(const char *hex, const char *prefix, cha
 
 static int write_tar_gzip_archive(const char *hex, const char *prefix)
 {
-	char *argv[] = { "gzip", "-n", NULL };
+	const char *argv[] = { "gzip", "-n", NULL };
 
 	return write_compressed_tar_archive(hex, prefix, argv);
 }
 
 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
 {
-	char *argv[] = { "bzip2", NULL };
+	const char *argv[] = { "bzip2", NULL };
 
 	return write_compressed_tar_archive(hex, prefix, argv);
 }
 
 static int write_tar_lzip_archive(const char *hex, const char *prefix)
 {
-	char *argv[] = { "lzip", NULL };
+	const char *argv[] = { "lzip", NULL };
 
 	return write_compressed_tar_archive(hex, prefix, argv);
 }
 
 static int write_tar_xz_archive(const char *hex, const char *prefix)
 {
-	char *argv[] = { "xz", NULL };
+	const char *argv[] = { "xz", NULL };
 
 	return write_compressed_tar_archive(hex, prefix, argv);
 }
@@ -131,7 +131,7 @@ static int write_tar_zstd_archive(const char *hex, const char *prefix)
 {
 	// Single-threaded like the other compressors, since -T0 would let one
 	// request pin every core.
-	char *argv[] = { "zstd", NULL };
+	const char *argv[] = { "zstd", NULL };
 
 	return write_compressed_tar_archive(hex, prefix, argv);
 }