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-rw-r--r--path.c112
1 files changed, 85 insertions, 27 deletions
diff --git a/path.c b/path.c
index 4e7fae4..3d244d3 100644
--- a/path.c
+++ b/path.c
@@ -434,42 +434,100 @@ int adjust_shared_perm(const char *path)
return 0;
}
-const char *relative_path(const char *abs, const char *base)
+/*
+ * Give path as relative to prefix.
+ *
+ * The strbuf may or may not be used, so do not assume it contains the
+ * returned path.
+ */
+const char *relative_path(const char *in, const char *prefix,
+ struct strbuf *sb)
{
- static char buf[PATH_MAX + 1];
+ int in_len = in ? strlen(in) : 0;
+ int prefix_len = prefix ? strlen(prefix) : 0;
+ int in_off = 0;
+ int prefix_off = 0;
int i = 0, j = 0;
- if (!base || !base[0])
- return abs;
- while (base[i]) {
- if (is_dir_sep(base[i])) {
- if (!is_dir_sep(abs[j]))
- return abs;
- while (is_dir_sep(base[i]))
+ if (!in_len)
+ return "./";
+ else if (!prefix_len)
+ return in;
+
+ while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
+ if (is_dir_sep(prefix[i])) {
+ while (is_dir_sep(prefix[i]))
i++;
- while (is_dir_sep(abs[j]))
+ while (is_dir_sep(in[j]))
j++;
+ prefix_off = i;
+ in_off = j;
+ } else {
+ i++;
+ j++;
+ }
+ }
+
+ if (
+ /* "prefix" seems like prefix of "in" */
+ i >= prefix_len &&
+ /*
+ * but "/foo" is not a prefix of "/foobar"
+ * (i.e. prefix not end with '/')
+ */
+ prefix_off < prefix_len) {
+ if (j >= in_len) {
+ /* in="/a/b", prefix="/a/b" */
+ in_off = in_len;
+ } else if (is_dir_sep(in[j])) {
+ /* in="/a/b/c", prefix="/a/b" */
+ while (is_dir_sep(in[j]))
+ j++;
+ in_off = j;
+ } else {
+ /* in="/a/bbb/c", prefix="/a/b" */
+ i = prefix_off;
+ }
+ } else if (
+ /* "in" is short than "prefix" */
+ j >= in_len &&
+ /* "in" not end with '/' */
+ in_off < in_len) {
+ if (is_dir_sep(prefix[i])) {
+ /* in="/a/b", prefix="/a/b/c/" */
+ while (is_dir_sep(prefix[i]))
+ i++;
+ in_off = in_len;
+ }
+ }
+ in += in_off;
+ in_len -= in_off;
+
+ if (i >= prefix_len) {
+ if (!in_len)
+ return "./";
+ else
+ return in;
+ }
+
+ strbuf_reset(sb);
+ strbuf_grow(sb, in_len);
+
+ while (i < prefix_len) {
+ if (is_dir_sep(prefix[i])) {
+ strbuf_addstr(sb, "../");
+ while (is_dir_sep(prefix[i]))
+ i++;
continue;
- } else if (abs[j] != base[i]) {
- return abs;
}
i++;
- j++;
}
- if (
- /* "/foo" is a prefix of "/foo" */
- abs[j] &&
- /* "/foo" is not a prefix of "/foobar" */
- !is_dir_sep(base[i-1]) && !is_dir_sep(abs[j])
- )
- return abs;
- while (is_dir_sep(abs[j]))
- j++;
- if (!abs[j])
- strcpy(buf, ".");
- else
- strcpy(buf, abs + j);
- return buf;
+ if (!is_dir_sep(prefix[prefix_len - 1]))
+ strbuf_addstr(sb, "../");
+
+ strbuf_addstr(sb, in);
+
+ return sb->buf;
}
/*