issue-13257.patch

From e71429b44e906508771bd5cdf51430e9fa3bc319 Mon Sep 17 00:00:00 2001
From: Stefan Eissing <stefan@eissing.org>
Date: Mon, 1 Apr 2024 15:41:18 +0200
Subject: [PATCH 1/3] chunked POST forced, disable length check on read
 callback

- when an application forces HTTP/1.1 chunked transfer encoding
  by setting the corresponding header and instructs curl to use
  the CURLOPT_READFUNCTION, disregard any POST length information.
- this establishes backward compatibility with previous curl versions

Applications are encouraged to not force "chunked", but rather
set length information for a POST. By setting -1, curl will
auto-select chunked on HTTP/1.1 and work properly on other HTTP
versions.
---
 lib/http.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/http.c b/lib/http.c
index 92c04e69cd8373..e37899675efecf 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -2046,8 +2046,13 @@ static CURLcode set_reader(struct Curl_easy *data, Curl_HttpReq httpreq)
       else
         result = Curl_creader_set_null(data);
     }
-    else { /* we read the bytes from the callback */
-      result = Curl_creader_set_fread(data, postsize);
+    else {
+      /* we read the bytes from the callback. In case "chunked" encoding
+       * is forced by the application, we disregard `postsize`. This is
+       * a backward compatibility decision to earlier versions where
+       * chunking disregarded this. See issue #13229. */
+      bool chunked = !!Curl_checkheaders(data, STRCONST("Transfer-Encoding"));
+      result = Curl_creader_set_fread(data, chunked? -1 : postsize);
     }
     return result;
 

From 0184f02cb23e2af48a8b68d26e972742488f6855 Mon Sep 17 00:00:00 2001
From: Stefan Eissing <stefan@eissing.org>
Date: Mon, 1 Apr 2024 16:57:09 +0200
Subject: [PATCH 2/3] Handle application enforced shunked encoding on HTTP/2
 and higher

- ignore application desire to chunk on HTTP/2 and higher
- give information message that chunked encoding is suppressed
---
 lib/http.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/http.c b/lib/http.c
index e37899675efecf..7eebd1026f8237 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -2120,6 +2120,13 @@ CURLcode Curl_http_req_set_reader(struct Curl_easy *data,
     data->req.upload_chunky =
       Curl_compareheader(ptr,
                          STRCONST("Transfer-Encoding:"), STRCONST("chunked"));
+    if(data->req.upload_chunky &&
+       Curl_use_http_1_1plus(data, data->conn) &&
+       (data->conn->httpversion >= 20)) {
+       infof(data, "suppressing chunked transfer encoding on connection "
+             "using HTTP version 2 or higher");
+       data->req.upload_chunky = FALSE;
+    }
   }
   else {
     curl_off_t req_clen = Curl_creader_total_length(data);

From d8aab07f5cf1eec5a1755765d35d69122727f565 Mon Sep 17 00:00:00 2001
From: Stefan Eissing <stefan@eissing.org>
Date: Mon, 1 Apr 2024 17:14:50 +0200
Subject: [PATCH 3/3] check TE header for "chunked" when ignoring post size

---
 lib/http.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/http.c b/lib/http.c
index 7eebd1026f8237..a764d3c4403c39 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -2051,7 +2051,13 @@ static CURLcode set_reader(struct Curl_easy *data, Curl_HttpReq httpreq)
        * is forced by the application, we disregard `postsize`. This is
        * a backward compatibility decision to earlier versions where
        * chunking disregarded this. See issue #13229. */
-      bool chunked = !!Curl_checkheaders(data, STRCONST("Transfer-Encoding"));
+      bool chunked = FALSE;
+      char *ptr = Curl_checkheaders(data, STRCONST("Transfer-Encoding"));
+      if(ptr) {
+        /* Some kind of TE is requested, check if 'chunked' is chosen */
+        chunked = Curl_compareheader(ptr, STRCONST("Transfer-Encoding:"),
+                                     STRCONST("chunked"));
+      }
       result = Curl_creader_set_fread(data, chunked? -1 : postsize);
     }
     return result;