b7ca6a235122ec881dcdb6951fe3fc1fcab49acd
max
  Wed Oct 1 09:37:20 2025 -0700
fixing error 500 on /list/files in the API, no ticket number yet as this is a build patch which requires a commit-ID

diff --git src/hg/hubApi/list.c src/hg/hubApi/list.c
index 77bb60992b8..41d484bd010 100644
--- src/hg/hubApi/list.c
+++ src/hg/hubApi/list.c
@@ -728,31 +728,31 @@
  */
 {
 long long itemsReturned = 0;
 boolean genArkHub = FALSE;
 char genArkUrl[PATH_MAX + 1024];
 
 if ( isGenArk(genome) )
     {
     genArkHub = TRUE;
     safef(genArkUrl, sizeof(genArkUrl), "hubs/%s", genArkPath(genome));
     }
 
 /* if UCSC genome database, it has already been proven to exist */
 
 struct jsonWrite *jw = NULL;
-boolean doContext = (cgiInt(argSkipContext)==0);
+boolean doContext = (cgiOptionalInt(argSkipContext, 0)==0);
 if (textOut && doContext)
     {
     char outString[1024];
     safef(outString, sizeof(outString), "# genome: %s", genome);
     textLineOut(outString);
   safef(outString, sizeof(outString), "# rsyncHost: rsync://%s", DOWNLOAD_HOST);
     textLineOut(outString);
     }
 else
     {
     jw = apiStartOutput();
     if (doContext)
         {
         jsonWriteString(jw, "genome", genome);
         jsonWriteString(jw, "rsyncHost", "rsync://" DOWNLOAD_HOST);