Fix valgrind issues and leaks

This fixes up a number of problems flagged by valgrind and also
cleans up the internal `git_submodule` allocation handling
overall with a simpler model.

src/buffer.c

@@ -144,31 +144,40 @@ int git_buf_puts(git_buf *buf, const char *string)
 int git_buf_puts_escaped(
 	git_buf *buf, const char *string, const char *esc_chars, const char *esc_with)
 {
-	const char *scan = string;
-	size_t total = 0, esc_with_len = strlen(esc_with);
+	const char *scan;
+	size_t total = 0, esc_len = strlen(esc_with), count;
 
-	while (*scan) {
-		size_t count = strcspn(scan, esc_chars);
-		total += count + 1 + esc_with_len;
-		scan += count + 1;
+	if (!string)
+		return 0;
+
+	for (scan = string; *scan; ) {
+		/* count run of non-escaped characters */
+		count = strcspn(scan, esc_chars);
+		total += count;
+		scan += count;
+		/* count run of escaped characters */
+		count = strspn(scan, esc_chars);
+		total += count * (esc_len + 1);
+		scan += count;
 	}
 
 	ENSURE_SIZE(buf, buf->size + total + 1);
 
 	for (scan = string; *scan; ) {
-		size_t count = strcspn(scan, esc_chars);
+		count = strcspn(scan, esc_chars);
 
 		memmove(buf->ptr + buf->size, scan, count);
 		scan += count;
 		buf->size += count;
 
-		if (*scan) {
-			memmove(buf->ptr + buf->size, esc_with, esc_with_len);
-			buf->size += esc_with_len;
-
-			memmove(buf->ptr + buf->size, scan, 1);
-			scan += 1;
-			buf->size += 1;
+		for (count = strspn(scan, esc_chars); count > 0; --count) {
+			/* copy escape sequence */
+			memmove(buf->ptr + buf->size, esc_with, esc_len);
+			buf->size += esc_len;
+			/* copy character to be escaped */
+			buf->ptr[buf->size] = *scan;
+			buf->size++;
+			scan++;
 		}
 	}
 

src/config_file.c

@@ -195,7 +195,7 @@ static int file_foreach(
 	void *data)
 {
 	diskfile_backend *b = (diskfile_backend *)backend;
-	cvar_t *var;
+	cvar_t *var, *next_var;
 	const char *key;
 	regex_t regex;
 	int result = 0;
@@ -212,7 +212,9 @@ static int file_foreach(
 	}
 
 	git_strmap_foreach(b->values, key, var,
-		for (; var != NULL; var = CVAR_LIST_NEXT(var)) {
+		for (; var != NULL; var = next_var) {
+			next_var = CVAR_LIST_NEXT(var);
+
 			/* skip non-matching keys if regexp was provided */
 			if (regexp && regexec(&regex, key, 0, NULL, 0) != 0)
 				continue;

src/fileops.c

@@ -700,6 +700,7 @@ int git_futils_cp_r(
 	error = _cp_r_callback(&info, &path);
 
 	git_buf_free(&path);
+	git_buf_free(&info.to);
 
 	return error;
 }

tests-clar/submodule/modify.c

@@ -253,4 +253,5 @@ void test_submodule_modify__edit_and_save(void)
 		(int)GIT_SUBMODULE_UPDATE_REBASE, (int)git_submodule_update(sm2));
 
 	git_repository_free(r2);
+	git__free(old_url);
 }

tests-clar/valgrind-supp-mac.txt

+{
+   libgit2-giterr-set-buffer
+   Memcheck:Leak
+   ...
+   fun:git__realloc
+   fun:git_buf_try_grow
+   fun:git_buf_grow
+   fun:git_buf_vprintf
+   fun:giterr_set
+}
+{
+   mac-setenv-leak-1
+   Memcheck:Leak
+   fun:malloc_zone_malloc
+   fun:__setenv
+   fun:setenv
+}
+{
+   mac-setenv-leak-2
+   Memcheck:Leak
+   fun:malloc_zone_malloc
+   fun:malloc_set_zone_name
+   ...
+   fun:init__zone0
+   fun:setenv
+}
+{
+   mac-dyld-initializer-leak
+   Memcheck:Leak
+   fun:malloc
+   ...
+   fun:dyld_register_image_state_change_handler
+   fun:_dyld_initializer
+}
+{
+   mac-tz-leak-1
+   Memcheck:Leak
+   ...
+   fun:token_table_add
+   fun:notify_register_check
+   fun:notify_register_tz
+}
+{
+   mac-tz-leak-2
+   Memcheck:Leak
+   fun:malloc
+   fun:tzload
+}
+{
+   mac-tz-leak-3
+   Memcheck:Leak
+   fun:malloc
+   fun:tzsetwall_basic
+}
+{
+   mac-tz-leak-4
+   Memcheck:Leak
+   fun:malloc
+   fun:gmtsub
+}
+{
+   mac-system-init-leak-1
+   Memcheck:Leak
+   ...
+   fun:_libxpc_initializer
+   fun:libSystem_initializer
+}
+{
+   mac-system-init-leak-2
+   Memcheck:Leak
+   ...
+   fun:__keymgr_initializer
+   fun:libSystem_initializer
+}
+{
+   mac-puts-leak
+   Memcheck:Leak
+   fun:malloc
+   fun:__smakebuf
+   ...
+   fun:puts
+}