X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=path.c;h=79aa104712364a8c18964feecd4c8079449a78cf;hb=aa14013abf27637dc2a2c0bee56fb98a981ee08d;hp=00d06332959af03b036b3d0b5ad115dd3b46b920;hpb=03c6e97f809e5b89089a2c689d6a319e8d471455;p=git.git

diff --git a/path.c b/path.c
index 00d063329..79aa10471 100644
--- a/path.c
+++ b/path.c
@@ -394,17 +394,38 @@ int set_shared_perm(const char *path, int mode)
 const char *make_relative_path(const char *abs, const char *base)
 {
 	static char buf[PATH_MAX + 1];
-	int baselen;
-	if (!base)
-		return abs;
-	baselen = strlen(base);
-	if (prefixcmp(abs, base))
+	int i = 0, j = 0;
+
+	if (!base || !base[0])
 		return abs;
-	if (abs[baselen] == '/')
-		baselen++;
-	else if (base[baselen - 1] != '/')
+	while (base[i]) {
+		if (is_dir_sep(base[i])) {
+			if (!is_dir_sep(abs[j]))
+				return abs;
+			while (is_dir_sep(base[i]))
+				i++;
+			while (is_dir_sep(abs[j]))
+				j++;
+			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;
-	strcpy(buf, abs + baselen);
+	while (is_dir_sep(abs[j]))
+		j++;
+	if (!abs[j])
+		strcpy(buf, ".");
+	else
+		strcpy(buf, abs + j);
 	return buf;
 }
 
@@ -581,3 +602,50 @@ char *strip_path_suffix(const char *path, const char *suffix)
 		return NULL;
 	return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
 }
+
+int daemon_avoid_alias(const char *p)
+{
+	int sl, ndot;
+
+	/*
+	 * This resurrects the belts and suspenders paranoia check by HPA
+	 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
+	 * does not do getcwd() based path canonicalizations.
+	 *
+	 * sl becomes true immediately after seeing '/' and continues to
+	 * be true as long as dots continue after that without intervening
+	 * non-dot character.
+	 */
+	if (!p || (*p != '/' && *p != '~'))
+		return -1;
+	sl = 1; ndot = 0;
+	p++;
+
+	while (1) {
+		char ch = *p++;
+		if (sl) {
+			if (ch == '.')
+				ndot++;
+			else if (ch == '/') {
+				if (ndot < 3)
+					/* reject //, /./ and /../ */
+					return -1;
+				ndot = 0;
+			}
+			else if (ch == 0) {
+				if (0 < ndot && ndot < 3)
+					/* reject /.$ and /..$ */
+					return -1;
+				return 0;
+			}
+			else
+				sl = ndot = 0;
+		}
+		else if (ch == 0)
+			return 0;
+		else if (ch == '/') {
+			sl = 1;
+			ndot = 0;
+		}
+	}
+}