06d7be056190c14b85e71bc12523f18ea6815b5e
markd
  Mon Dec 7 00:50:29 2020 -0800
BLAT mmap index support merge with master

diff --git src/hg/hgTracks/mainMain.c src/hg/hgTracks/mainMain.c
index 94d5bab..dbe437c 100644
--- src/hg/hgTracks/mainMain.c
+++ src/hg/hgTracks/mainMain.c
@@ -40,30 +40,31 @@
 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");
     errAbortSetDoContentType(FALSE);
     cart = cartForSession(hUserCookie(), NULL, NULL);
     extToolRedirect(cart, cgiString("hgt.redirectTool"));
     }
 else
     cartHtmlShell("UCSC Genome Browser v"CGI_VERSION, doMiddle, hUserCookie(), excludeVars, oldVars);
 
 // TODO: better place for this ?
 puts("<link rel=\"stylesheet\" href=\"https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css\">\n");
 
 if (measureTiming)
     measureTime("Time to write and close cart");
 if (measureTiming)
     {