fc8de100a3437b9fc33bdeb0f459ca2a93e2f318
max
  Wed Sep 9 08:14:32 2026 -0700
hgSession: address the code review of the new Sessions page

Rename and unshare now keep the public listing's thumbnail with the session it
belongs to.  The picture's file name is built from the encoded session name, so
renaming a listed session left the listing pointing at nothing and the old file
behind, and dropping a session from the listing to a plain shared link kept the
picture.  The classic page had the same problem in a subtler form: it removed the
thumbnail after the row had already been renamed, so the old file survived.

Saving under a name that is already in use asks before it replaces that session,
using the failIfExists reply that the top-right Share a link menu already relies
on.  The description and "only I can load it" steps that follow a save now report
a failure instead of reloading in silence, and what thumbnailAdd has to say when
it cannot build a picture reaches the user instead of being freed unread.

A session description no longer travels through a title attribute.  The tooltip
machinery in utils.js inserts its text with innerHTML and an attribute is decoded
on the way, so a description containing angle brackets was interpreted as markup
rather than shown as typed.  It is attached, escaped, after each table draw, which
also gives the rows DataTables renders later the same styled mouseovers as the
rest of the page.

Also: the AJAX endpoints say so when there is no session by that name, instead of
reporting a no-op as a success; the new page always offers its way back to the
classic page, since the cart variable that got the user there sticks; and four
unused CSS rules, a dead element lookup and a dead local are gone.  hgConfCatalog
cited the wrong ticket for the two sessionNewPage flags.

refs #38180, refs #38157

diff --git src/hg/htdocs/style/hgSession.css src/hg/htdocs/style/hgSession.css
index f676de31f9b..e9ea331902e 100644
--- src/hg/htdocs/style/hgSession.css
+++ src/hg/htdocs/style/hgSession.css
@@ -1,101 +1,96 @@
 /* hgSession.css - session-specific layout for the modern "My Sessions" page (hgSession.js).
  *
  * The shared UCSC house-style components (tokens, .gbPill, .gbBanner, .gbCard, .gbModal*,
  * .gbSection, .gbShareBox, .gbTable) live in gbModern.css, loaded alongside this file via
  * webIncludeResourceFile.  This file only holds the pieces unique to the sessions page: the
  * save-current-view card, the session table's columns, and the Advanced panel. */
 
 /* The whole app sits in #sessionApp, which also carries class "gbApp" for the design tokens. */
 #sessionApp { margin:12px 0 24px; }
 #sessionApp .sessIntro { font-size:14px; color:var(--ink); margin:0 0 14px; }
 #sessionApp .sessIntro a { color:var(--accent); }
 #sessionApp .sessIntro a:hover { color:var(--accentHover); }
 
 /* Save-current-view card - the primary action.  Neutral light-grey panel. */
 #sessionApp .sessSaveCard { border:0; background:#f6f8fa; padding:14px 16px;
     display:flex; flex-direction:column; gap:12px; margin:0 0 20px; }
 #sessionApp .sessSaveHead { display:flex; align-items:baseline; gap:12px; flex-wrap:wrap; }
 /* Title and the current-view summary share one font size (title is just bold). */
 #sessionApp .sessSaveTitle { font-size:14px; font-weight:700; color:var(--accent); }
 #sessionApp .sessSaveWhat { font-size:14px; }
 #sessionApp .sessSaveRow { display:flex; align-items:center; gap:12px; flex-wrap:wrap; }
 #sessionApp .sessSaveInput { flex:1 1 320px; min-width:220px; height:34px; box-sizing:border-box;
     padding:0 11px; font-size:14px; border:1px solid var(--btnLine); border-radius:0; background:#fff;
     font-family:inherit; }
 /* The optional description input spans the card on its own line below the name row. */
 #sessionApp #sessSaveDesc { width:100%; flex:none; }
 #sessionApp .sessSaveCheck { display:flex; align-items:center; gap:7px; font-size:13px;
     color:var(--ink); white-space:nowrap; }
 
 /* One-click "update the most recently saved session" - a compact thin bar above the save card. */
 #sessionApp .sessRecent { display:flex; align-items:center; gap:8px; flex-wrap:wrap;
     border:0; background:#f6f8fa; padding:6px 12px; font-size:14px; margin:0 0 12px; }
 #sessionApp .sessRecent .gbPill { padding:2px 10px; }
 #sessionApp .sessRecentTime { color:var(--muted); }
 /* Info bubble (navy circled i) used for the recent-update hint and session descriptions. */
 #sessionApp .sessInfo { color:var(--accent); cursor:help; font-size:15px; line-height:1; }
 
 /* Section heading ("Your saved sessions") separating the save card from the table. */
 #sessionApp .gbSection { margin-top:4px; }
 
-/* Toolbar above the table: DataTables search box + count + import/export. */
+/* Toolbar above the table: DataTables search box, page-length menu and the Select button. */
 #sessionApp .sessToolbar { display:flex; align-items:center; gap:14px; flex-wrap:wrap; margin:0 0 10px; }
-#sessionApp .sessCount { font-size:13px; color:var(--muted); white-space:nowrap; }
-#sessionApp .sessToolbarActions { margin-left:auto; display:flex; gap:8px; align-items:center; }
 #sessionApp #sessionAppTable_length { margin:0; font-size:14px; color:var(--ink); }
 #sessionApp #sessionAppTable_length select { border:1px solid var(--btnLine); border-radius:0;
     padding:4px 6px; font-size:14px; background:#fff; margin:0 4px; }
 #sessionApp #sessionAppTable_filter { margin:0; }
 #sessionApp #sessionAppTable_filter input { width:280px; max-width:55vw; border:1px solid var(--btnLine);
     border-radius:0; padding:5px 9px; font-size:14px; }
 #sessionApp #sessionAppTable_wrapper { overflow-x:auto; }
 
 /* Session table columns.  Left-align every header and cell (including Actions) for one clean edge. */
 #sessionAppTable thead th, #sessionAppTable tbody td { text-align:left; }
 /* Bulk-select checkbox column (hidden until "Select" is pressed). */
 #sessionAppTable td.sessSelCol, #sessionAppTable th.sessSelCol { width:26px; text-align:center; }
 #sessionAppTable td.sessNameCol a { font-weight:700; }
 /* Saved region (band, locus, Mbp position), shown inline after the assembly at normal text
  * size and color, separated by whitespace. */
 #sessionAppTable .sessPos { white-space:nowrap; }
-#sessionAppTable td.sessDescCol { max-width:280px; white-space:nowrap; overflow:hidden;
-    text-overflow:ellipsis; color:var(--muted); }
 #sessionAppTable td.sessActionsCol { white-space:nowrap; }
 /* All action controls (text and icon-only) share one height so they line up. */
 #sessionAppTable td.sessActionsCol .gbPill { display:inline-flex; align-items:center;
     justify-content:center; height:24px; padding:0 9px; font-size:12px; margin-left:5px;
     box-sizing:border-box; vertical-align:middle; }
 #sessionAppTable td.sessActionsCol .gbPill.danger { padding:0 8px; }
 #sessionAppTable .sessIcon { width:17px; height:17px; display:block; }
-#sessionAppTable .sessShareIcon { vertical-align:-2px; margin-right:4px; }
 #sessionAppTable .sessPublic { display:inline-block; margin-left:6px; font-size:11px; font-weight:700;
     color:#1f7a34; }
 /* Lock marks a private (not-shared) session; sharing is the default so only the exception is marked. */
 #sessionAppTable .sessLockWrap { margin-left:6px; cursor:help; }
 #sessionAppTable .sessLock { width:10px; height:12px; display:inline-block; vertical-align:-2px;
     color:var(--muted); }
 
 /* Advanced collapsible - the rarer load/backup/reset options.  Collapsed it is a thin bar; sits
  * between the save card and the sessions table. */
 #sessionApp .sessAdv { border:0; margin:0 0 20px; }
 #sessionApp .sessAdvHead { display:flex; align-items:center; gap:9px; padding:11px 14px;
     background:#f6f8fa; cursor:pointer; font-size:14px; font-weight:700; color:var(--accent);
     user-select:none; }
 #sessionApp .sessAdvHead .caret { width:12px; display:inline-block; }
 #sessionApp .sessAdvBody { padding:16px 16px; display:grid; grid-template-columns:1fr 1fr;
     gap:18px 28px; background:#f6f8fa; font-size:14px; }
 @media (max-width:820px) { #sessionApp .sessAdvBody { grid-template-columns:1fr; } }
 #sessionApp .sessAdvItem { display:flex; flex-direction:column; gap:7px; }
 #sessionApp .sessAdvItem > .lab { font-weight:700; color:var(--ink); }
 #sessionApp .sessAdvRow { display:flex; gap:8px; flex-wrap:wrap; align-items:center; }
 #sessionApp .sessAdvInput { flex:1 1 140px; min-width:110px; height:32px; box-sizing:border-box;
     border:1px solid var(--btnLine); border-radius:0; padding:0 9px; font-size:14px; background:#fff;
     font-family:inherit; }
 #sessionApp .sessAdvLinks { display:flex; gap:16px; flex-wrap:wrap; }
 #sessionApp .sessAdvLinks a { color:var(--accent); }
 #sessionApp .sessAdvLinks a:hover { color:var(--accentHover); }
 
 /* Small inline status line for AJAX feedback (errors in maroon). */
 #sessionApp .sessMsg { font-size:13px; margin:0 0 12px; }
 #sessionApp .sessMsg.err { color:#b1301f; font-weight:700; }
 #sessionApp .sessMsg.ok { color:#1f7a34; }