Chaser Zaks commented at 2018-08-28T18:39:42Z, updated at 2018-08-28T18:41:18Z

I put a thingy west bound of http://maps.secondlife.com/secondlife/Testylvania%20Sandbox/108/161/21 which appears to reproduce this from the description. Object and scripts are full perm and shared with the Testylvanian group if need be to poke at the thing.

From a web development standpoint, updating(not replacing) the URL in CEF would make sense as it follows anchor links and triggers the "hashchange" window event in javascript.
Example implementation on how this would be fixed(in pseudo code):

//Example URL: https://secondlife.com/example/document.htm?key=value#anything
//Splitting it into a "path" would cause:
//origin: <protocol>://<host>[:port] (https://secondlife.com)
//pathname: [slash separated string] (/example/document.htm)
//querystring: [?[key=value[&...]]
//hashstring: [#[anything]]


path currentUrl;
media change message(path url)
    if(url.origin == currentUrl.origin && url.pathname == currentUrl.pathname && url.querystring == currentUrl.querystring)
        if(url.hashstring != currentUrl.hashstring)
            update url(Cause the "hashchange" window event, don't cause a navigation event(refresh/reload/etc))
        
        //else do nothing
    
    else
        replace url(Cause navigation event)
    
    currentUrl = url;

Whirly Fizzle commented at 2018-08-28T21:06:29Z

Confirmed Chaser's test page at https://felix.softhyena.com/BUG-225356.htm reproduces the bug on post-Alex Ivy viewers but not on pre-Alex Ivy viewers.

Clicking on the bottom ?test link followed by the top #test link.

• On Alex Ivy viewers: Bottom link fires change event 2048 (CHANGED_MEDIA), top link does not.
• On Pre-Alex Ivy viewers: Bottom link fires change event 2048 (CHANGED_MEDIA), top link fires change event 2048 (CHANGED_MEDIA).

Oz Linden commented at 2018-09-05T16:03:55Z, updated at 2018-09-05T22:20:58Z

Can you make a simple LSL script that illustrates the problem without picking up all of a HUD?

and it would appear from Chasers demo that appending/modifying a query parameter does still generate the Changed event.  Is there a reason why you can't use that?  There's nothing wrong with the server ignoring parameters it doesn't care about.

Whirly Fizzle commented at 2018-09-07T14:33:32Z

• Rez a box & make it a suitable size for a media screen.

• Add the following script to the box

  list sites = [
      "https://felix.softhyena.com/BUG-225356.htm?test=0.8990316884092033"
  ];
  
  string currentUrl;
  
  setupMedia(string url){
      llSetPrimMediaParams(2, [
          PRIM_MEDIA_ALT_IMAGE_ENABLE, FALSE,
          PRIM_MEDIA_CONTROLS, PRIM_MEDIA_CONTROLS_STANDARD,
          PRIM_MEDIA_CURRENT_URL, url,
          PRIM_MEDIA_HOME_URL, url,
          PRIM_MEDIA_AUTO_LOOP, TRUE,
          PRIM_MEDIA_AUTO_PLAY, TRUE,
          PRIM_MEDIA_AUTO_SCALE, TRUE,
          PRIM_MEDIA_AUTO_ZOOM, FALSE,
          PRIM_MEDIA_FIRST_CLICK_INTERACT, TRUE,
          PRIM_MEDIA_WIDTH_PIXELS, 1024,
          PRIM_MEDIA_HEIGHT_PIXELS, 1024,
          PRIM_MEDIA_WHITELIST_ENABLE, FALSE,
          PRIM_MEDIA_WHITELIST, "",
          PRIM_MEDIA_PERMS_INTERACT, PRIM_MEDIA_PERM_ANYONE,
          PRIM_MEDIA_PERMS_CONTROL, PRIM_MEDIA_PERM_ANYONE
      ]);
  }
  
  setMediaUrl(string url){
      llSay(0, "Media set to "+url);
      llSetPrimMediaParams(2, [
          PRIM_MEDIA_CURRENT_URL, url
      ]);
  }
  
  list getChanges(integer change){
      list evt;
      if((CHANGED_INVENTORY&change) == CHANGED_INVENTORY)evt = evt + "CHANGED_INVENTORY";
      if((CHANGED_COLOR&change) == CHANGED_COLOR)evt = evt + "CHANGED_COLOR";
      if((CHANGED_SHAPE&change) == CHANGED_SHAPE)evt = evt + "CHANGED_SHAPE";
      if((CHANGED_SCALE&change) == CHANGED_SCALE)evt = evt + "CHANGED_SCALE";
      if((CHANGED_TEXTURE&change) == CHANGED_TEXTURE)evt = evt + "CHANGED_TEXTURE";
      if((CHANGED_LINK&change) == CHANGED_LINK)evt = evt + "CHANGED_LINK";
      if((CHANGED_ALLOWED_DROP&change) == CHANGED_ALLOWED_DROP)evt = evt + "CHANGED_ALLOWED_DROP";
      if((CHANGED_OWNER&change) == CHANGED_OWNER)evt = evt + "CHANGED_OWNER";
      if((CHANGED_REGION&change) == CHANGED_REGION)evt = evt + "CHANGED_REGION";
      if((CHANGED_TELEPORT&change) == CHANGED_TELEPORT)evt = evt + "CHANGED_TELEPORT";
      if((CHANGED_REGION_START&change) == CHANGED_REGION_START)evt = evt + "CHANGED_REGION_START";
      if((CHANGED_MEDIA&change) == CHANGED_MEDIA)evt = evt + "CHANGED_MEDIA";
      return evt;
  }
  
  default{
      state_entry(){
          llSetLinkPrimitiveParamsFast(1, [
              PRIM_TEXT, "BUG-225356 Repro", <1,1,1>, 1,
          PRIM_LINK_TARGET, 2,
              PRIM_TEXT, "Click to reset URL", <1,1,1>, 1,
          PRIM_LINK_TARGET, 3,
              PRIM_TEXT, "Click to append \"#test=<random>\" via LSL", <1,1,1>, 1
          ]);
          currentUrl = llList2String(sites, llFloor(llFrand(llGetListLength(sites))));
          setupMedia(currentUrl);
      }
  
      touch_start(integer total_number){
          integer i = llDetectedLinkNumber(0);
          if(i == 2){
              currentUrl = llList2String(sites, llFloor(llFrand(llGetListLength(sites))));
              setMediaUrl(currentUrl);
          }else if(i == 3){
              setMediaUrl(currentUrl+"#test="+(string)llFrand(1));
          }
      }
      
      changed(integer c){
          llSay(0, "I received change event "+(string)c+" ("+llDumpList2String(getChanges(c), "|")+")");   
      }
  }

• On the media face, click the bottom ?test link & observe in local chat that a CHANGED_MEDIA event is fired.

• Click the top #test link & observe that no CHANGED_MEDIA event is fired.

• On Pre-Alex Ivy viewers, both the ?test and the #test links produce a CHANGED_MEDIA event.