f02bb3ce9489bb2c922188ebf94f52a0e80dd757
braney
  Mon Jul 5 10:45:34 2021 -0700
change system() calls to pipeline() calls.

diff --git src/hg/hgSession/hgSession.c src/hg/hgSession/hgSession.c
index de76c75..fef41d6 100644
--- src/hg/hgSession/hgSession.c
+++ src/hg/hgSession/hgSession.c
@@ -909,33 +909,34 @@
  * add a warning message to dyMessage unless the hg.conf setting
  * sessionThumbnail.suppressWarning is set to "on".
  * Leaks memory from a generated filename string, plus a couple of dyStrings.
  * Returns without determining if image creation succeeded (it happens in a separate
  * thread); the return value is 0 if a message was added to dyMessage, otherwise it's 1. */
 {
 char query[4096];
 
 char *suppressConvert = cfgOption("sessionThumbnail.suppress");
 if (suppressConvert != NULL && sameString(suppressConvert, "on"))
     return 1;
 
 char *convertPath = cfgOption("sessionThumbnail.convertPath");
 if (convertPath == NULL)
     convertPath = cloneString("convert");
-char convertTestCmd[4096];
-safef(convertTestCmd, sizeof(convertTestCmd), "which %s > /dev/null", convertPath);
-int convertTestResult = system(convertTestCmd);
+char *whichCmd[] = {"which", convertPath, NULL};
+struct pipeline *pl = pipelineOpen1(whichCmd, pipelineWrite | pipelineNoAbort, "/dev/null", NULL);
+int convertTestResult = pipelineWait(pl);
+
 if (convertTestResult != 0)
     {
     dyStringPrintf(dyMessage,
          "Note: A thumbnail image for this session was not created because the ImageMagick convert "
          "tool could not be found.  Please contact your mirror administrator to resolve this "
          "issue, either by installing convert so that it is part of the webserver's PATH, "
          "by adding the \"sessionThumbnail.convertPath\" option to the mirror's hg.conf file "
          "to specify the path to that program, or by adding \"sessionThumbnail.suppress=on\" to "
          "the mirror's hg.conf file to suppress this warning.<br>");
     return 0;
     }
 
 sqlSafef(query, sizeof(query),
     "select firstUse from namedSessionDb where userName = \"%s\" and sessionName = \"%s\"",
     encUserName, encSessionName);