Set STREAM_PROTOCOL_PATH for any module if stream has already been loaded.

Note that any module that depends on StreamDevice will load it first using `handleDependencies` which
is called before we add the _DB paths. So if a module depends on StreamDevice, this will be accurately
caught; moreover, if StreamDevice is not loaded, then we don't bother setting this path.

require-ess/src/require.c

@@ -352,6 +352,8 @@ char *realpathSeparator(const char *location) {
   return buffer;
 }
 
+int isModuleLoaded(const char *libname);
+
 static int setupDbPath(const char *module, const char *dbdir) {
   char *absdir =
       realpathSeparator(dbdir); /* so we can change directory later safely */
@@ -373,6 +375,9 @@ static int setupDbPath(const char *module, const char *dbdir) {
 
   putenvprintf("%s_DB=%s", module, absdir);
   putenvprintf("TEMPLATES=%s", absdir);
+  if (isModuleLoaded("stream")) {
+    pathAdd("STREAM_PROTOCOL_PATH", absdir);
+  }
   pathAdd("EPICS_DB_INCLUDE_PATH", absdir);
   free(absdir);
   return 0;
@@ -727,6 +732,16 @@ const char *getLibLocation(const char *libname) {
   return NULL;
 }
 
+int isModuleLoaded(const char *libname) {
+  moduleitem *m;
+
+  for (m = loadedModules; m; m = m->next) {
+    if (strcmp(m->content, libname) == 0)
+      return TRUE;
+  }
+  return FALSE;
+}
+
 int libversionShow(const char *outfile) {
   moduleitem *m;
   size_t lm, lv;