block: Make path_combine() return the path
Besides being safe for arbitrary path lengths, after some follow-up
patches all callers will want a freshly allocated buffer anyway.
In the meantime, path_combine_deprecated() is added which has the same
interface as path_combine() had before this patch. All callers to that
function will be converted in follow-up patches.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20190201192935.18394-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/block.c b/block.c
index 3b33941..91859a9 100644
--- a/block.c
+++ b/block.c
@@ -152,53 +152,62 @@
#endif
}
-/* if filename is absolute, just copy it to dest. Otherwise, build a
+/* if filename is absolute, just return its duplicate. Otherwise, build a
path to it by considering it is relative to base_path. URL are
supported. */
-void path_combine(char *dest, int dest_size,
- const char *base_path,
- const char *filename)
+char *path_combine(const char *base_path, const char *filename)
{
+ const char *protocol_stripped = NULL;
const char *p, *p1;
+ char *result;
int len;
- if (dest_size <= 0)
- return;
if (path_is_absolute(filename)) {
- pstrcpy(dest, dest_size, filename);
- } else {
- const char *protocol_stripped = NULL;
-
- if (path_has_protocol(base_path)) {
- protocol_stripped = strchr(base_path, ':');
- if (protocol_stripped) {
- protocol_stripped++;
- }
- }
- p = protocol_stripped ?: base_path;
-
- p1 = strrchr(base_path, '/');
-#ifdef _WIN32
- {
- const char *p2;
- p2 = strrchr(base_path, '\\');
- if (!p1 || p2 > p1)
- p1 = p2;
- }
-#endif
- if (p1)
- p1++;
- else
- p1 = base_path;
- if (p1 > p)
- p = p1;
- len = p - base_path;
- if (len > dest_size - 1)
- len = dest_size - 1;
- memcpy(dest, base_path, len);
- dest[len] = '\0';
- pstrcat(dest, dest_size, filename);
+ return g_strdup(filename);
}
+
+ if (path_has_protocol(base_path)) {
+ protocol_stripped = strchr(base_path, ':');
+ if (protocol_stripped) {
+ protocol_stripped++;
+ }
+ }
+ p = protocol_stripped ?: base_path;
+
+ p1 = strrchr(base_path, '/');
+#ifdef _WIN32
+ {
+ const char *p2;
+ p2 = strrchr(base_path, '\\');
+ if (!p1 || p2 > p1) {
+ p1 = p2;
+ }
+ }
+#endif
+ if (p1) {
+ p1++;
+ } else {
+ p1 = base_path;
+ }
+ if (p1 > p) {
+ p = p1;
+ }
+ len = p - base_path;
+
+ result = g_malloc(len + strlen(filename) + 1);
+ memcpy(result, base_path, len);
+ strcpy(result + len, filename);
+
+ return result;
+}
+
+static void path_combine_deprecated(char *dest, int dest_size,
+ const char *base_path,
+ const char *filename)
+{
+ char *combined = path_combine(base_path, filename);
+ pstrcpy(dest, dest_size, combined);
+ g_free(combined);
}
/*
@@ -316,7 +325,7 @@
error_setg(errp, "Cannot use relative backing file names for '%s'",
backed);
} else {
- path_combine(dest, sz, backed, backing);
+ path_combine_deprecated(dest, sz, backed, backing);
}
}
@@ -4657,8 +4666,8 @@
} else {
/* If not an absolute filename path, make it relative to the current
* image's filename path */
- path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
- backing_file);
+ path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename,
+ backing_file);
/* We are going to compare absolute pathnames */
if (!realpath(filename_tmp, filename_full)) {
@@ -4667,8 +4676,8 @@
/* We need to make sure the backing filename we are comparing against
* is relative to the current image filename (or absolute) */
- path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
- curr_bs->backing_file);
+ path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename,
+ curr_bs->backing_file);
if (!realpath(filename_tmp, backing_file_full)) {
continue;