cb99f0b11bdeee5dfa76064d38b6410da0f4a709
max
  Thu Sep 10 00:55:21 2026 -0700
Centralize CGI Content-Type printing in one cgiPrintContentType() helper

Around 90 places across the tree hand-rolled the CGI response header, each
with its own spelling: "Content-Type:" or "Content-type:", \n or \r\n, and
the terminating blank line written as part of the same string, as a separate
puts("\n") (which emits two newlines, so a stray blank line led the body) or
as printf("\r\n\r\n") (two blank lines).  A handful forgot the terminator
entirely and relied on a following header to supply it.

cgiPrintContentType() in lib/cheapcgi.c now writes the Content-Type line and
the blank line that ends the header.  Header lines are not ordered, so the
callers that also send Status, Set-Cookie, Content-Disposition, Content-Length
or X-Sendfile write those first and call this last to close the header; that
keeps it to a single helper rather than a print-the-line / end-the-header pair
that a caller can half-use.  cart.c's existing httpHeaders list already worked
this way.

Only the CGI response path is touched.  The dyStringPrintf("Content-type: ...")
calls that build outgoing HTTP *requests* (genomeSpace, oauthLogin, eapMetaSync,
edwWebAuthLogin, ga4ghToBed) are unrelated and left alone.

Also fills out the apiKey error message in botDelay.c to say where to create a
key and that keys are server-specific.

No behavior change on the wire beyond dropping those stray blank lines and
adding the missing newline after Retry-After.

diff --git src/hg/cgilib/cartJson.c src/hg/cgilib/cartJson.c
index 0bf5c2f92a0..43a6adc726e 100644
--- src/hg/cgilib/cartJson.c
+++ src/hg/cgilib/cartJson.c
@@ -933,31 +933,31 @@
 pushWarnHandler(cartJsonVaWarn);
 pushAbortHandler(cartJsonAbort);
 }
 
 void cartJsonPopErrHandlers()
 /* Pop warn and abort handlers for errAbort. */
 {
 popWarnHandler();
 popAbortHandler();
 }
 
 void cartJsonExecute(struct cartJson *cj)
 /* Get commands from cgi, print Content-type, execute commands, print results as JSON. */
 {
 cartJsonPushErrHandlers();
-puts("Content-Type:text/javascript\n");
+cgiPrintContentType("text/javascript");
 
 // Initialize response JSON object:
 jsonWriteObjectStart(cj->jw, NULL);
 // Always send back hgsid:
 jsonWriteString(cj->jw, cartSessionVarName(), cartSessionId(cj->cart));
 
 char *commandJson = cgiOptionalString(CARTJSON_COMMAND);
 if (commandJson)
     {
     struct errCatch *errCatch = errCatchNew();
     if (errCatchStart(errCatch))
         {
         struct jsonElement *commandObj = jsonParse(commandJson);
         struct hash *commandHash = jsonObjectVal(commandObj, "commandObj");
         // change* commands need to go first!  Really we need an ordered map type here...