When I do curl -I curl.se, my terminal (Konsole) does not include the leading whitespace in the link.

alacritty, foot and kitty include the space. I believe Konsole disables escape sequences for links by default.

Ah, now I see the problem. Isn't this patch simpler?

diff --git a/src/tool_cb_hdr.c b/src/tool_cb_hdr.c
index aab96ae03..b1bad12e0 100644
--- a/src/tool_cb_hdr.c
+++ b/src/tool_cb_hdr.c
@@ -399,12 +399,12 @@ void write_linked_location(CURL *curl, const char *location, size_t loclen,
 
   if(!strcmp("http", scheme) ||
      !strcmp("https", scheme) ||
      !strcmp("ftp", scheme) ||
      !strcmp("ftps", scheme)) {
-    fprintf(stream, LINK "%s" LINKST "%.*s" LINKOFF,
-            finalurl, (int)loclen, location);
+    fprintf(stream, " " LINK "%s" LINKST "%.*s" LINKOFF,
+            finalurl, (int)loclen, loc);
     goto locdone;
   }
 
   /* Not a "safe" URL: don't linkify it */

I believe Konsole disables escape sequences for links by default.

No it doesn't. At least I get it linkified just fine.

Or maybe this is even better:

diff --git a/src/tool_cb_hdr.c b/src/tool_cb_hdr.c
index aab96ae03..878e8a563 100644
--- a/src/tool_cb_hdr.c
+++ b/src/tool_cb_hdr.c
@@ -399,12 +399,12 @@ void write_linked_location(CURL *curl, const char *location, size_t loclen,
 
   if(!strcmp("http", scheme) ||
      !strcmp("https", scheme) ||
      !strcmp("ftp", scheme) ||
      !strcmp("ftps", scheme)) {
-    fprintf(stream, LINK "%s" LINKST "%.*s" LINKOFF,
-            finalurl, (int)loclen, location);
+    fprintf(stream, " " LINK "%s" LINKST "%s" LINKOFF "\n",
+            finalurl, copyloc);
     goto locdone;
   }
 
   /* Not a "safe" URL: don't linkify it */
 

/cc @dfandrich

I had thought of fixing it like that. Is there a chance that not specifying the length will lead to bugs?

Not that I can spot since copyloc is a null-terminated string it should be fine. But I still would like to get @dfandrich to chime in, he wrote this code.

The original intention was to preserve the whitespace so the user gets the same output with or without styling enabled (modula the styling, of course). The proposed patch strips leading whitespace and replaces it with a single character, which is often, but not always, the same. I didn't bother eliminating the leading whitespace from the linked section, but I can see how it could be annoying on some terminals.

What I would probably do instead is count the amount of whitespace stripped in the /* Strip leading whitespace of the redirect URL */ loop by adding a ++space_skipped in the loop, then change the fprintf to:

    fprintf(stream, "%.*s" LINK "%s" LINKST "%.*s" LINKOFF,
             space_skipped, location, finalurl, (int)loclen - space_skipped, loc);

This is untested but the idea is to print the leading whitespace as-is, then the rest of the linkification without that leading space.

Thanks!