Merge branch 'backport/jk/libcurl-8.7-regression-workaround' into maint-2.39

Fix was added to work around a regression in libcURL 8.7.0 (which has
already been fixed in their tip of the tree).

* jk/libcurl-8.7-regression-workaround:
  remote-curl: add Transfer-Encoding header only for older curl
  INSTALL: bump libcurl version to 7.21.3
  http: reset POSTFIELDSIZE when clearing curl handle

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>

4 files changed, 14 insertions, 1 deletions

diff --git a/INSTALL b/INSTALL
index d5694f8c47..232314ec7d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -139,7 +139,7 @@ Issues of note:
 	  not need that functionality, use NO_CURL to build without
 	  it.
 
-	  Git requires version "7.19.5" or later of "libcurl" to build
+	  Git requires version "7.21.3" or later of "libcurl" to build
 	  without NO_CURL. This version requirement may be bumped in
 	  the future.
 
diff --git a/git-curl-compat.h b/git-curl-compat.h
index fd96b3cdff..e1d0bdd273 100644
--- a/git-curl-compat.h
+++ b/git-curl-compat.h
@@ -127,6 +127,15 @@
 #endif
 
 /**
+ * Versions before curl 7.66.0 (September 2019) required manually setting the
+ * transfer-encoding for a streaming POST; after that this is handled
+ * automatically.
+ */
+#if LIBCURL_VERSION_NUM < 0x074200
+#define GIT_CURL_NEED_TRANSFER_ENCODING_HEADER
+#endif
+
+/**
  * CURLOPT_PROTOCOLS_STR and CURLOPT_REDIR_PROTOCOLS_STR were added in 7.85.0,
  * released in August 2022.
  */
diff --git a/http.c b/http.c
index ca3737e5c0..92c5a22f26 100644
--- a/http.c
+++ b/http.c
@@ -1326,6 +1326,7 @@ struct active_request_slot *get_active_slot(void)
 	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 	curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, -1L);
 	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
diff --git a/remote-curl.c b/remote-curl.c
index a76b6405eb..322cd0f9f4 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "git-curl-compat.h"
 #include "config.h"
 #include "remote.h"
 #include "connect.h"
@@ -953,7 +954,9 @@ retry:
 		/* The request body is large and the size cannot be predicted.
 		 * We must use chunked encoding to send it.
 		 */
+#ifdef GIT_CURL_NEED_TRANSFER_ENCODING_HEADER
 		headers = curl_slist_append(headers, "Transfer-Encoding: chunked");
+#endif
 		rpc->initial_buffer = 1;
 		curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, rpc_out);
 		curl_easy_setopt(slot->curl, CURLOPT_INFILE, rpc);