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/hgTracks/mainMain.c src/hg/hgTracks/mainMain.c
index fce837d8279..e827e3191a6 100644
--- src/hg/hgTracks/mainMain.c
+++ src/hg/hgTracks/mainMain.c
@@ -1,103 +1,103 @@
 /* hgTracks - Human Genome browser main cgi script. */
 
 /* Copyright (C) 2013 The Regents of the University of California 
  * See kent/LICENSE or http://genome.ucsc.edu/license/ for licensing information. */
 
 #include "common.h"
 #include "linefile.h"
 #include "portable.h"
 #include "memalloc.h"
 #include "localmem.h"
 #include "hCommon.h"
 #include "obscure.h"
 #include "dystring.h"
 #include "hash.h"
 #include "cheapcgi.h"
 #include "htmshell.h"
 #include "web.h"
 #include "cart.h"
 #include "hdb.h"
 #include "hui.h"
 #include "hgFind.h"
 #include "hgTracks.h"
 #include "versionInfo.h"
 #include "net.h"
 #include "search.h"
 #include "imageV2.h"
 #include "extTools.h"
 #include "botDelay.h"
 #include "hgConfig.h"
 #include <sys/time.h>
 #include <sys/resource.h>
 
 boolean issueBotWarning;
 long enteredMainTime = 0;
 
 int main(int argc, char *argv[])
 {
 // First, before anything has a chance to allocate: read hg.conf and set how
 // big a step the C library takes when it grows the heap.  refs #38225
 cfgSetMallocTopPad();
 
 enteredMainTime = clock1000();
 measureTime(NULL);
 
 // This is generic CGI setup code: Should be moved one day into a generic function 
 // combined with the code cart.c:genericCgiSetup() ?
 cfgSetMaxMem(); // read hg.conf and set the maxMem if there
 cfgSetLogCgiVars(); // set logging of the CGI vars
 
 issueBotWarning = earlyBotCheck(enteredMainTime, "hgTracks", delayFraction, 0, 0, "html");
 browserName = hBrowserName();
 organization = "UCSC";
 
 /* Push very early error handling - this is just
  * for the benefit of the cgiVarExists, which
  * somehow can't be moved effectively into doMiddle. */
 htmlPushEarlyHandlers();
 cgiSpoof(&argc, argv);
 char * link = webTimeStampedLinkToResourceOnFirstCall("HGStyle.css",TRUE); // resource file link
 if (link)                                                                  // wrapped in html
     htmlSetStyle(link);
 
 oldVars = hashNew(10);
 
 if (cgiVarExists("hgt.redirectTool"))
     {
     // user has selected one of the tools in View > In external tools: Do not plot, just redirect.
-    printf("Content-type: text/html\n\n");
+    cgiPrintContentType("text/html");
     errAbortSetDoContentType(FALSE);
     cart = cartForSession(hUserCookie(), NULL, NULL);
     extToolRedirect(cart, cgiString("hgt.redirectTool"));
     }
 else if (cfgOptionBooleanDefault("doMyVariants", FALSE) && cgiVarExists("myVarShareCmd"))
     {
     cart = cartForSession(hUserCookie(), NULL, NULL);
     myVariantsShareApiHandler(cgiString("myVarShareCmd"));
     }
 else
     {
     httpHeaders = slPairNew("Cache-Control", "no-store");
     cartHtmlShell("UCSC Genome Browser v"CGI_VERSION, doMiddle, hUserCookie(), excludeVars, oldVars);
     }
 
 // TODO: better place for this ?
 webIncludeResourceFile("font-awesome.min.css");
 
 if (measureTiming)
     measureTime("Time to write and close cart");
 if (measureTiming)
     {
     fprintf(stdout, "<span class='timing'>Overall total time: %ld millis<br /></span>\n",
             clock1000() - enteredMainTime);
     }
 cgiExitTime("hgTracks", enteredMainTime);
 
 // print out some resource usage stats
 struct rusage usage;
 int stat = getrusage(RUSAGE_SELF, &usage);
 if (stat == 0)
     // if you change this printf, then increment the number after RESOURCE:
     fprintf(stderr, "RESOURCE: 1 %ld %ld %ld\n",usage.ru_utime.tv_sec,usage.ru_stime.tv_sec, usage.ru_maxrss);
 return 0;
 }