From 345b0c0c464a793b1eaca0dd50352c8a2487f769 Mon Sep 17 00:00:00 2001
From: kai-yin <kai-yin@u-nas.cn>
Date: Tue, 1 Jun 2021 16:47:27 +0800
Subject: [PATCH 1/3] Check the file url into a complete url to support
 onlyoffice documentservice behind a reverse proxy with extra parts in url.

---
 lib/documentservice.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/documentservice.php b/lib/documentservice.php
index 308d1d68..e9d8ce1d 100644
--- a/lib/documentservice.php
+++ b/lib/documentservice.php
@@ -97,7 +97,12 @@ function GetConvertedUri($document_uri, $from_extension, $to_extension, $documen
         $isEndConvert = $responceFromConvertService->EndConvert;
 
         if ($isEndConvert !== null && strtolower($isEndConvert) === "true") {
-            return $responceFromConvertService->FileUrl;
+            $fileUrl = $responceFromConvertService->FileUrl;
+            if ( strpos($fileUrl, "http://") !== 0 && strpos($fileUrl, "https://") !== 0 ){
+                $url = parse_url($document_uri);
+                $fileUrl = $url["scheme"]."://".$url['host'].$fileUrl ;
+            }
+            return $fileUrl;
         }
 
         return "";

From 9cd412d084e8aac5943415fb580e32cd66dda81b Mon Sep 17 00:00:00 2001
From: kai-yin <kai-yin@u-nas.cn>
Date: Thu, 3 Jun 2021 10:43:57 +0800
Subject: [PATCH 2/3] Optimise the judge of incomplete url and add the port
 part of url.

---
 lib/documentservice.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/documentservice.php b/lib/documentservice.php
index e9d8ce1d..cda97d99 100644
--- a/lib/documentservice.php
+++ b/lib/documentservice.php
@@ -98,10 +98,11 @@ function GetConvertedUri($document_uri, $from_extension, $to_extension, $documen
 
         if ($isEndConvert !== null && strtolower($isEndConvert) === "true") {
             $fileUrl = $responceFromConvertService->FileUrl;
-            if ( strpos($fileUrl, "http://") !== 0 && strpos($fileUrl, "https://") !== 0 ){
+            if ( !preg_match("/^https?:\/\//i", $fileUrl) ){
                 $url = parse_url($document_uri);
-                $fileUrl = $url["scheme"]."://".$url['host'].$fileUrl ;
+                $fileUrl = $url["scheme"] . "://" . $url['host'] . (array_key_exists("port", $url) ? (":" . $url["port"]) : "") . $fileUrl ;
             }
+
             return $fileUrl;
         }
 

From 90ebcbd3842ca4d7fa9b21c9eeaf1b5a421edd71 Mon Sep 17 00:00:00 2001
From: kai-yin <kai-yin@u-nas.cn>
Date: Thu, 3 Jun 2021 10:45:47 +0800
Subject: [PATCH 3/3] Convert an incomplete url into a complete one.

---
 lib/appconfig.php | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/lib/appconfig.php b/lib/appconfig.php
index 3d0d6f34..c33cbe6c 100644
--- a/lib/appconfig.php
+++ b/lib/appconfig.php
@@ -457,11 +457,27 @@ public function GetDocumentServerInternalUrl($origin = false) {
      * @return string
      */
     public function ReplaceDocumentServerUrlToInternal($url) {
+        // GetDocumentServerInternalUrl() will be the same with GetDocumentServerUrl() if internal url is not specified.
         $documentServerUrl = $this->GetDocumentServerInternalUrl();
+
         if (!empty($documentServerUrl)) {
             $from = $this->GetDocumentServerUrl();
 
+            if (!preg_match("/^https?:\/\//i", $url)){
+                // $url is not a complete url. Form it with $from
+                $parsedUrl = parse_url($from);
+
+                // $url may include VPATH. Judge it to avoid dupe.
+                // https://github.com/ONLYOFFICE/document-server-proxy/blob/master/apache/proxy-to-virtual-path.conf
+                $vpath = $parsedUrl["path"];
+                if (empty($vpath)){
+                    $vpath = "/";
+                }
+                $url = $from.preg_filter("#^$vpath#i", "", $url, 1);
+            }
+
             if (!preg_match("/^https?:\/\//i", $from)) {
+                // Frontend forbids input incomplete url, so this will never happen?
                 $parsedUrl = parse_url($url);
                 $from = $parsedUrl["scheme"] . "://" . $parsedUrl["host"] . (array_key_exists("port", $parsedUrl) ? (":" . $parsedUrl["port"]) : "") . $from;
             }