[PATCH v4 1/5] http: support file handles for HTTP_KEEP_ERROR

[Masaya Suzuki]

HTTP_KEEP_ERROR makes it easy to debug HTTP transport errors. In order
to make HTTP_KEEP_ERROR enabled for all requests, file handles need to
be supported.

Signed-off-by: Masaya Suzuki <masayasuz...@google.com>
---
 http.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/http.c b/http.c
index 0b6807cef9..4eccf4c5d8 100644
--- a/http.c
+++ b/http.c
@@ -1991,16 +1991,26 @@ static int http_request_reauth(const char *url,
        /*
         * If we are using KEEP_ERROR, the previous request may have
         * put cruft into our output stream; we should clear it out before
-        * making our next request. We only know how to do this for
-        * the strbuf case, but that is enough to satisfy current callers.
+        * making our next request.
         */
        if (options && options->keep_error) {
                switch (target) {
                case HTTP_REQUEST_STRBUF:
                        strbuf_reset(result);
                        break;
+               case HTTP_REQUEST_FILE:
+                       if (fflush(result)) {
+                               error_errno("unable to flush a file");
+                               return HTTP_START_FAILED;
+                       }
+                       rewind(result);
+                       if (ftruncate(fileno(result), 0) < 0) {
+                               error_errno("unable to truncate a file");
+                               return HTTP_START_FAILED;
+                       }
+                       break;
                default:
-                       BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+                       BUG("Unknown http_request target");
                }
        }
 
-- 
2.20.1.97.g81188d93c3-goog