fixup http: fix the max header length detection logicbagder/tests-long-headers

as verified by test 1154

1 files changed, 10 insertions, 11 deletions

diff --git a/lib/http.c b/lib/http.c
index f44b18ae9..c1c7b3908 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -2880,20 +2880,19 @@ static CURLcode header_append(struct Curl_easy *data,
                               struct SingleRequest *k,
                               size_t length)
 {
-  if(k->hbuflen + length >= data->state.headersize) {
+  size_t newsize = k->hbuflen + length;
+  if(newsize > CURL_MAX_HTTP_HEADER) {
+    /* The reason to have a max limit for this is to avoid the risk of a bad
+       server feeding libcurl with a never-ending header that will cause
+       reallocs infinitely */
+    failf(data, "Rejected %zd bytes header (max is %d)!", newsize,
+          CURL_MAX_HTTP_HEADER);
+    return CURLE_OUT_OF_MEMORY;
+  }
+  if(newsize >= data->state.headersize) {
     /* We enlarge the header buffer as it is too small */
     char *newbuff;
     size_t hbufp_index;
-    size_t newsize;
-
-    if(k->hbuflen + length > CURL_MAX_HTTP_HEADER) {
-      /* The reason to have a max limit for this is to avoid the risk of a bad
-         server feeding libcurl with a never-ending header that will cause
-         reallocs infinitely */
-      failf(data, "Avoided giant realloc for header (max is %d)!",
-            CURL_MAX_HTTP_HEADER);
-      return CURLE_OUT_OF_MEMORY;
-    }
 
     newsize = CURLMAX((k->hbuflen + length) * 3 / 2, data->state.headersize*2);
     hbufp_index = k->hbufp - data->state.headerbuff;