From def4d8986ee66d87db4d17a8a4c6fbaa4ddfc1df Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Mon, 13 Apr 2026 22:30:13 +0200
Subject: [PATCH] http: use header_has_value() instead of duplicate code

Closes #21302
---
 lib/http.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/lib/http.c b/lib/http.c
index d82459e738..a1e58e886c 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -166,17 +166,29 @@ char *Curl_checkProxyheaders(struct Curl_easy *data,
 }
 #endif
 
+/* If the header has a value, this function returns TRUE and the value is in
+   'outp' with blanks trimmed off.
+*/
+static bool header_has_value(const char **headerp, struct Curl_str *outp)
+{
+  bool value = !curlx_str_cspn(headerp, outp, ";:") &&
+    (!curlx_str_single(headerp, ':') || !curlx_str_single(headerp, ';'));
+
+  if(value) {
+    curlx_str_untilnl(headerp, outp, MAX_HTTP_RESP_HEADER_SIZE);
+    curlx_str_trimblanks(outp);
+  }
+  return value;
+}
+
 static bool http_header_is_empty(const char *header)
 {
   struct Curl_str out;
 
-  if(!curlx_str_cspn(&header, &out, ";:") &&
-     (!curlx_str_single(&header, ':') || !curlx_str_single(&header, ';'))) {
-    curlx_str_untilnl(&header, &out, MAX_HTTP_RESP_HEADER_SIZE);
-    curlx_str_trimblanks(&out);
+  if(header_has_value(&header, &out)) {
     return curlx_strlen(&out) == 0;
   }
-  return TRUE; /* invalid head format, treat as empty */
+  return TRUE; /* invalid header format, treat as empty */
 }
 
 /*
@@ -192,11 +204,7 @@ static CURLcode copy_custom_value(const char *header, char **valp)
   struct Curl_str out;
 
   /* find the end of the header name */
-  if(!curlx_str_cspn(&header, &out, ";:") &&
-     (!curlx_str_single(&header, ':') || !curlx_str_single(&header, ';'))) {
-    curlx_str_untilnl(&header, &out, MAX_HTTP_RESP_HEADER_SIZE);
-    curlx_str_trimblanks(&out);
-
+  if(header_has_value(&header, &out)) {
     *valp = curlx_memdup0(curlx_str(&out), curlx_strlen(&out));
     if(*valp)
       return CURLE_OK;