--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/dotdot.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,182 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#include <curl/curl.h>
+
+#include "dotdot.h"
+#include "curl_memory.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/*
+ * "Remove Dot Segments"
+ * https://tools.ietf.org/html/rfc3986#section-5.2.4
+ */
+
+/*
+ * Curl_dedotdotify()
+ * @unittest: 1395
+ *
+ * This function gets a zero-terminated path with dot and dotdot sequences
+ * passed in and strips them off according to the rules in RFC 3986 section
+ * 5.2.4.
+ *
+ * The function handles a query part ('?' + stuff) appended but it expects
+ * that fragments ('#' + stuff) have already been cut off.
+ *
+ * RETURNS
+ *
+ * an allocated dedotdotified output string
+ */
+char *Curl_dedotdotify(const char *input)
+{
+  size_t inlen = strlen(input);
+  char *clone;
+  size_t clen = inlen; /* the length of the cloned input */
+  char *out = malloc(inlen + 1);
+  char *outptr;
+  char *orgclone;
+  char *queryp;
+  if(!out)
+    return NULL; /* out of memory */
+
+  *out = 0; /* zero terminates, for inputs like "./" */
+
+  /* get a cloned copy of the input */
+  clone = strdup(input);
+  if(!clone) {
+    free(out);
+    return NULL;
+  }
+  orgclone = clone;
+  outptr = out;
+
+  if(!*clone) {
+    /* zero length string, return that */
+    free(out);
+    return clone;
+  }
+
+  /*
+   * To handle query-parts properly, we must find it and remove it during the
+   * dotdot-operation and then append it again at the end to the output
+   * string.
+   */
+  queryp = strchr(clone, '?');
+  if(queryp)
+    *queryp = 0;
+
+  do {
+
+    /*  A.  If the input buffer begins with a prefix of "../" or "./", then
+        remove that prefix from the input buffer; otherwise, */
+
+    if(!strncmp("./", clone, 2)) {
+      clone += 2;
+      clen -= 2;
+    }
+    else if(!strncmp("../", clone, 3)) {
+      clone += 3;
+      clen -= 3;
+    }
+
+    /*  B.  if the input buffer begins with a prefix of "/./" or "/.", where
+        "."  is a complete path segment, then replace that prefix with "/" in
+        the input buffer; otherwise, */
+    else if(!strncmp("/./", clone, 3)) {
+      clone += 2;
+      clen -= 2;
+    }
+    else if(!strcmp("/.", clone)) {
+      clone[1]='/';
+      clone++;
+      clen -= 1;
+    }
+
+    /*  C.  if the input buffer begins with a prefix of "/../" or "/..", where
+        ".." is a complete path segment, then replace that prefix with "/" in
+        the input buffer and remove the last segment and its preceding "/" (if
+        any) from the output buffer; otherwise, */
+
+    else if(!strncmp("/../", clone, 4)) {
+      clone += 3;
+      clen -= 3;
+      /* remove the last segment from the output buffer */
+      while(outptr > out) {
+        outptr--;
+        if(*outptr == '/')
+          break;
+      }
+      *outptr = 0; /* zero-terminate where it stops */
+    }
+    else if(!strcmp("/..", clone)) {
+      clone[2]='/';
+      clone += 2;
+      clen -= 2;
+      /* remove the last segment from the output buffer */
+      while(outptr > out) {
+        outptr--;
+        if(*outptr == '/')
+          break;
+      }
+      *outptr = 0; /* zero-terminate where it stops */
+    }
+
+    /*  D.  if the input buffer consists only of "." or "..", then remove
+        that from the input buffer; otherwise, */
+
+    else if(!strcmp(".", clone) || !strcmp("..", clone)) {
+      *clone = 0;
+      *out = 0;
+    }
+
+    else {
+      /*  E.  move the first path segment in the input buffer to the end of
+          the output buffer, including the initial "/" character (if any) and
+          any subsequent characters up to, but not including, the next "/"
+          character or the end of the input buffer. */
+
+      do {
+        *outptr++ = *clone++;
+        clen--;
+      } while(*clone && (*clone != '/'));
+      *outptr = 0;
+    }
+
+  } while(*clone);
+
+  if(queryp) {
+    size_t qlen;
+    /* There was a query part, append that to the output. The 'clone' string
+       may now have been altered so we copy from the original input string
+       from the correct index. */
+    size_t oindex = queryp - orgclone;
+    qlen = strlen(&input[oindex]);
+    memcpy(outptr, &input[oindex], qlen + 1); /* include the end zero byte */
+  }
+
+  free(orgclone);
+  return out;
+}