From b2ae19eed4073349ec8bee84007556ab8ded2ad0 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 1 Oct 2025 13:33:22 +0200
Subject: [PATCH] tool_getparam: warn if provided header looks malformed

URL: https://fosstodon.org/@galdor/115298664084113519
Closes #18793
---
 src/tool_getparam.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tool_getparam.c b/src/tool_getparam.c
index eed87bb807..60b3b30ad4 100644
--- a/src/tool_getparam.c
+++ b/src/tool_getparam.c
@@ -1267,6 +1267,10 @@ static ParameterError parse_header(struct OperationConfig *config,
     }
   }
   else {
+    if(!strchr(nextarg, ':') && !strchr(nextarg, ';')) {
+      warnf("The provided %s header '%s' does not look like a header?",
+            (cmd == C_PROXY_HEADER) ? "proxy": "HTTP", nextarg);
+    }
     if(cmd == C_PROXY_HEADER) /* --proxy-header */
       err = add2list(&config->proxyheaders, nextarg);
     else