d338d5080783d2ac5828658fe17160668bf64cdb
chmalee
  Thu May 7 15:05:24 2026 -0700
Fixes from code review, refs #37500

- Revalidate shared myVariants tracks against hgcentral on every read
path (hgTracks, hgc, hgTables); cart-supplied owner/db/project no
longer trusted. New myVariantsResolveSharedTrack helper.
- Scope shared-track UPDATE statements by share->project/db so a
recipient can't edit rows outside the granted scope.
- Add hgsid CSRF check to myVariantsJsCommand; pass hgsid in the
hgTracks.js highlight Add-Annotation POST.
- HTML-escape owner-controlled fields in the canEdit branch of
doMyVariantsDetails (Chromosome, Project, project select options,
hidden text input).
- Validate targetUser against gbMembers when creating a share; return
a clear 400 on typos.
- Replace the concat(id,' ',name)='%s' lookup with parsed-id +
name verification.
- Remove cgiMakeColorVar / cgiMakeColorVarWithLabel; the canEdit form
uses spectrum.js (already loaded for the create dialog).
- Strip _hidden_* columns from hgTables field lists for shared tracks,
both the display path and the selected-fields read path.
- Make the per-assembly invariant explicit: myVariantsLoadItems and
doMyVariantsDetails bail out if share->db != current database.
- Memoize myVariantsSharedScopeWhere to avoid per-region hgcentral
round-trips on genome-wide hgTables queries.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

diff --git src/hg/hgTracks/myVariantsTrack.c src/hg/hgTracks/myVariantsTrack.c
index 2ffee273a38..31cf394a06a 100644
--- src/hg/hgTracks/myVariantsTrack.c
+++ src/hg/hgTracks/myVariantsTrack.c
@@ -1,901 +1,907 @@
 /* myVariantsTrack.c - supports tracks of type myVariants.  Users can drag to create an item
  * and click to edit one. */
 
 /* Copyright (C) 2013 The Regents of the University of California 
  * See kent/LICENSE or http://genome.ucsc.edu/license/ for licensing information. */
 
 #include "common.h"
 #include "hash.h"
 #include "linefile.h"
 #include "jksql.h"
 #include "hdb.h"
 #include "hgTracks.h"
 #include "bed.h"
 #include "binRange.h"
 #include "myVariants.h"
 #include "myVariantsShare.h"
 #include "jsonParse.h"
 #include "sqlNum.h"
 #include "customFactory.h"
 #include "hgConfig.h"
 #include "htmlColor.h"
 #include "wikiLink.h"
 #include "hgFind.h"
 #include "jsonWrite.h"
 
 static char *reservedFieldNames[] = {
     "bin", "chrom", "chromStart", "chromEnd", "name", "score", "strand",
     "thickStart", "thickEnd", "itemRgb", "description", "db", "ref", "alt",
     "project", "mouseover", "id", NULL
 };
 
 static boolean isValidFieldName(char *name)
 /* Validate that name matches [a-zA-Z_][a-zA-Z0-9_]*, is not a reserved column name,
  * and does not start with _hidden_ */
 {
 if (isEmpty(name))
     return FALSE;
 if (startsWith("_hidden_", name))
     return FALSE;
 /* Check first char is letter or underscore */
 if (!isalpha(name[0]) && name[0] != '_')
     return FALSE;
 /* Check remaining chars are alphanumeric or underscore */
 int i;
 for (i = 1; name[i] != '\0'; i++)
     {
     if (!isalnum(name[i]) && name[i] != '_')
         return FALSE;
     }
 /* Check against reserved names */
 int j;
 for (j = 0; reservedFieldNames[j] != NULL; j++)
     {
     if (sameString(name, reservedFieldNames[j]))
         return FALSE;
     }
 return TRUE;
 }
 
 void myVariantsJsCommand(char *command, struct track *trackList, struct hash *trackHash)
 /* Execute some command sent to us from the javaScript.  All we know for sure is that
  * the first word of the command is "myVariants."  We expect it to be of format:
  *    myVariants <trackName> <jsonData>
  * where jsonData is a JSON string containing the item details */
 {
 if (!cfgOptionBooleanDefault("doMyVariants", FALSE))
     return;
 char *userName = getUserName();
 if (userName == NULL)
     return;
 
+/* This command runs mysql commands so require the hgsids match to prevent CSRF. */
+char *suppliedHgsid = cgiOptionalString("hgsid");
+char *expectedHgsid = cartSessionId(cart);
+if (isEmpty(suppliedHgsid) || isEmpty(expectedHgsid)
+    || !sameString(suppliedHgsid, expectedHgsid))
+    errAbort("session token missing or invalid");
+
 /* Parse out command into local variables. */
 char *words[3];
 char *dupeCommand = cloneString(command);	/* For parsing. */
 int wordCount = chopByWhiteRespectDoubleQuotes(dupeCommand, words, ArraySize(words));
 if (wordCount != 3)
    errAbort("Expecting %d words in jsCommand '%s'", wordCount, command);
 char *jsonData = words[2];
 
 /* Parse JSON data */
 struct jsonElement *json = jsonParse(jsonData);
 if (json == NULL)
     errAbort("Invalid JSON data in command: %s", jsonData);
 
 /* Handle hideField command: rename column with _hidden_ prefix */
 char *hideFieldName = jsonOptionalStringField(json, "hideField", NULL);
 if (isNotEmpty(hideFieldName))
     {
     if (isValidFieldName(hideFieldName))
         {
         char *tableName = myVariantsTableExists(userName);
         if (tableName)
             {
             struct sqlConnection *conn = hAllocConn(CUSTOM_TRASH);
             if (sqlFieldIndex(conn, tableName, hideFieldName) >= 0)
                 {
                 struct dyString *alterSql = sqlDyStringCreate(
                     "ALTER TABLE %s CHANGE COLUMN %s _hidden_%s varchar(255) DEFAULT NULL",
                     tableName, hideFieldName, hideFieldName);
                 sqlUpdate(conn, dyStringContents(alterSql));
                 dyStringFree(&alterSql);
                 }
             hFreeConn(&conn);
             }
         }
     freez(&dupeCommand);
     return;
     }
 
 /* Create a new item based on command. */
 struct myVariants *item;
 AllocVar(item);
 
 /* Extract values from JSON */
 struct jsonElement *hgvsJson = jsonFindNamedField(json, "jsonData", "hgvsInput");
 if (hgvsJson)
     {
     char *hgvs = jsonStringVal(hgvsJson, "hgvsInput");
     if (hgvs)
         {
         struct hgPositions *hgp = NULL;
         AllocVar(hgp);
         hgp->query = cloneString(hgvs);
         hgp->database = database;
         hgp->useAlias = FALSE;
         if (matchesHgvs(cart, database, hgvs, hgp, measureTiming))
             {
             fixSinglePos(hgp);
             if (hgp->singlePos)
                 {
                 // fill out an item AND redirect to that location somehow?
                 item->chrom = hgp->singlePos->chrom;
                 item->chromStart = item->thickStart = hgp->singlePos->chromStart;
                 item->chromEnd = item->thickEnd = hgp->singlePos->chromEnd;
                 item->strand[0] = '.';
                 item->score = 0;
                 item->bin = binFromRange(item->chromStart, item->chromEnd);
                 item->name = hgp->singlePos->name;
                 item->ref = cloneString("");
                 item->alt = cloneString("");
                 item->db = database;
                 item->description = cloneString(hgp->singlePos->description);
                 item->project = cloneString("");
                 item->mouseover = cloneString("");
                 }
             }
         else
             {
             /* HGVS didn't match - try hgFind for position/gene resolution */
             struct hgPositions *hgpFind = hgPositionsFind(database, hgvs,
                 "", "myVariants", cart, FALSE, FALSE, NULL);
             if (hgpFind != NULL && hgpFind->posCount == 1)
                 {
                 struct hgPos *pos = hgpFind->singlePos;
                 item->chrom = cloneString(pos->chrom);
                 item->chromStart = item->thickStart = pos->chromStart;
                 item->chromEnd = item->thickEnd = pos->chromEnd;
                 item->strand[0] = '.';
                 item->score = 0;
                 item->bin = binFromRange(item->chromStart, item->chromEnd);
                 item->name = cloneString(pos->name ? pos->name : hgvs);
                 item->ref = cloneString("");
                 item->alt = cloneString("");
                 item->db = database;
                 item->description = cloneString(pos->description ? pos->description : "");
                 item->project = cloneString("");
                 item->mouseover = cloneString("");
                 }
             else if (hgpFind != NULL && hgpFind->posCount > 1)
                 {
                 warn("Position '%s' matches %d locations - please be more specific", hgvs, hgpFind->posCount);
                 return;
                 }
             else
                 {
                 warn("Position '%s' not found", hgvs);
                 return;
                 }
             }
         }
     }
 else
     {
     char *chrom = jsonStringVal(jsonFindNamedField(json, "jsonData", "chrom"), "chrom");
     int chromStart = sqlUnsigned(jsonStringVal(jsonFindNamedField(json, "jsonData", "start"), "start"));
     int chromEnd = sqlUnsigned(jsonStringVal(jsonFindNamedField(json, "jsonData", "end"), "end"));
     char *name = jsonStringVal(jsonFindNamedField(json, "jsonData", "name"), "name");
     int score = sqlUnsigned(jsonStringVal(jsonFindNamedField(json, "jsonData", "score"), "score"));
     char *strand = jsonStringVal(jsonFindNamedField(json, "jsonData", "strand"), "strand");
     int thickStart = sqlUnsigned(jsonStringVal(jsonFindNamedField(json, "jsonData", "thickStart"), "thickStart"));
     int thickEnd = sqlUnsigned(jsonStringVal(jsonFindNamedField(json, "jsonData", "thickEnd"), "thickEnd"));
     char *colorCode = jsonStringVal(jsonFindNamedField(json, "jsonData", "color"), "color");
     char *description = jsonStringVal(jsonFindNamedField(json, "jsonData", "description"), "description");
     char *ref = jsonOptionalStringField(json, "ref", "");
     char *alt = jsonOptionalStringField(json, "alt", "");
     char *project = jsonOptionalStringField(json, "project", "");
     char *mouseover = jsonOptionalStringField(json, "mouseover", "");
     unsigned color;
     htmlColorForCode(colorCode, &color);
 
     item->bin = binFromRange(chromStart, chromEnd);
     item->chrom = cloneString(chrom);
     item->chromStart = chromStart;
     item->chromEnd = chromEnd;
     item->thickStart = thickStart;
     item->thickEnd = thickEnd;
     item->name = cloneString(name);
     item->score = score;
     item->strand[0] = strand[0];
     item->itemRgb = color;
     item->description = cloneString(description);
     item->ref = cloneString(ref);
     item->alt = cloneString(alt);
     item->db = database;
     item->project = cloneString(project);
     item->mouseover = cloneString(mouseover);
     }
 
 if (!item)
     return;
 
 /* Parse custom fields from JSON payload and ALTER TABLE as needed */
 char *tableName = myVariantsCreateTable(userName);
 struct sqlConnection *conn = hAllocConn(CUSTOM_TRASH);
 
 struct jsonElement *extraFieldsJson = jsonFindNamedField(json, "jsonData", "extraFields");
 if (extraFieldsJson && extraFieldsJson->type == jsonList)
     {
     struct slRef *el;
     for (el = extraFieldsJson->val.jeList; el != NULL; el = el->next)
         {
         struct jsonElement *cfObj = el->val;
         char *cfName = jsonOptionalStringField(cfObj, "name", NULL);
         char *cfValue = jsonOptionalStringField(cfObj, "value", "");
         if (isEmpty(cfName) || !isValidFieldName(cfName))
             continue;
         /* Add column if it doesn't already exist; un-hide if hidden */
         if (sqlFieldIndex(conn, tableName, cfName) < 0)
             {
             char hiddenName[256];
             safef(hiddenName, sizeof(hiddenName), "_hidden_%s", cfName);
             if (sqlFieldIndex(conn, tableName, hiddenName) >= 0)
                 {
                 /* Un-hide: rename _hidden_X back to X */
                 struct dyString *alterSql = sqlDyStringCreate(
                     "ALTER TABLE %s CHANGE COLUMN %s %s varchar(255) DEFAULT NULL",
                     tableName, hiddenName, cfName);
                 sqlUpdate(conn, dyStringContents(alterSql));
                 dyStringFree(&alterSql);
                 }
             else
                 {
                 struct dyString *alterSql = sqlDyStringCreate(
                     "ALTER TABLE %s ADD COLUMN %s varchar(255) DEFAULT NULL", tableName, cfName);
                 sqlUpdate(conn, dyStringContents(alterSql));
                 dyStringFree(&alterSql);
                 }
             }
         slPairAdd(&item->customFields, cfName, cloneString(cfValue));
         }
     slReverse(&item->customFields);
     }
 
 /* Add item to database. */
 myVariantsSaveToDb(conn, item, tableName, 0);
 
 /* Trigger CT import by writing a concrete CT file to trash and pointing ctfile_<db> to it */
 char *ctFile = myVariantsWriteCtFile(userName, database, cart);
 if (isNotEmpty(ctFile))
     {
     char varName[256];
     safef(varName, sizeof varName, CT_FILE_VAR_PREFIX "%s", database);
     cartSetString(cart, varName, ctFile);
     freeMem(ctFile);
     }
 
 /* Output new item coordinates for JavaScript to use for navigation */
 jsInlineF("// START newItemPos\n");
 jsInlineF("var newItemPos = {\"chrom\": \"%s\", \"start\": %d, \"end\": %d};\n",
           item->chrom, item->chromStart, item->chromEnd);
 jsInlineF("// END newItemPos\n");
 
 hFreeConn(&conn);
 
 freez(&dupeCommand);
 }
 
 static int myVariantsExtraHeight(struct track *track)
 /* Return extra height of track. */
 {
 return tl.fontHeight+2;
 }
 
 static void updateTextField(char *trackName, struct sqlConnection *conn,
-	char *tableName, char *fieldName, int id)
-/* Update text valued field with new val. */
+	char *tableName, char *fieldName, int id, char *scopeProject, char *scopeDb)
+/* Update text valued field with new val. If scopeProject/scopeDb are non-NULL,
+ * include them in the WHERE clause so a recipient cannot edit rows outside
+ * the share's authorized project/db. scopeProject of "*" means all projects. */
 {
 char varName[128];
 safef(varName, sizeof(varName), "%s_%s", trackName, fieldName);
 char *newVal = cartOptionalString(cart, varName);
 if (newVal == NULL)
     return;
 if (endsWith(varName, "itemRgb"))
     {
     unsigned color;
     if (htmlColorForCode(newVal, &color))
         {
-        char sql[256];
-        sqlSafef(sql, sizeof(sql), "update %s set %s='%d' where id=%d",
-            tableName, fieldName, color, id);
-        sqlUpdate(conn, sql);
+        struct dyString *sql = sqlDyStringCreate(
+            "update %s set %s='%d' where id=%d", tableName, fieldName, color, id);
+        if (isNotEmpty(scopeDb))
+            sqlDyStringPrintf(sql, " and db='%s'", scopeDb);
+        if (isNotEmpty(scopeProject) && !sameString(scopeProject, "*"))
+            sqlDyStringPrintf(sql, " and project='%s'", scopeProject);
+        sqlUpdate(conn, sql->string);
+        dyStringFree(&sql);
         cartRemove(cart, varName);
         }
     return;
     }
 struct dyString *sql = sqlDyStringCreate("update %s set %s='%s' where id=%d",
     tableName, fieldName, newVal, id);
+if (isNotEmpty(scopeDb))
+    sqlDyStringPrintf(sql, " and db='%s'", scopeDb);
+if (isNotEmpty(scopeProject) && !sameString(scopeProject, "*"))
+    sqlDyStringPrintf(sql, " and project='%s'", scopeProject);
 sqlUpdate(conn, sql->string);
 dyStringFree(&sql);
 cartRemove(cart, varName);
 }
 
 static void myVariantsEditOrDelete(char *trackName, struct sqlConnection *conn, char *tableName)
 /* Troll through cart variables looking for things that indicate user edited item
  * or deleted it in hgc,  and carry out edits. See hgc/myVariantsClick.c. */
 {
 char varName[128];
 char sql[256];
 safef(varName, sizeof(varName), "%s_%s", trackName, "id");
 char *idString = cartOptionalString(cart, varName);
 if (idString != NULL)
     {
     int id = sqlUnsigned(idString);
     idString = NULL; // Will be no good after cartRemove
     cartRemove(cart, varName); // Remove so only do edits once.
 
     /* Handle cancel. */
     safef(varName, sizeof(varName), "%s_%s", trackName, "cancel");
     if (cartVarExists(cart, varName))
         {
         cartRemove(cart, varName); // Only want to do cancels once
         return;
         }
 
     /* Handle delete. */
     safef(varName, sizeof(varName), "%s_%s", trackName, "delete");
     if (cartVarExists(cart, varName))
         {
         cartRemove(cart, varName);	// Especially only want to do deletes once!
         sqlSafef(sql, sizeof(sql), "delete from %s where id=%d", tableName, id);
         sqlUpdate(conn, sql);
         /* Trigger CT refresh */
         char *userName = getUserName();
         if (userName)
             {
             char *ctFile = myVariantsWriteCtFile(userName, database, cart);
             if (isNotEmpty(ctFile))
                 {
                 char ctVar[256];
                 safef(ctVar, sizeof ctVar, CT_FILE_VAR_PREFIX "%s", database);
                 cartSetString(cart, ctVar, ctFile);
                 freeMem(ctFile);
                 }
             }
         return;
         }
 
-    /* Handle edits. */
-    updateTextField(trackName, conn, tableName, "name", id);
-    updateTextField(trackName, conn, tableName, "description", id);
-    updateTextField(trackName, conn, tableName, "itemRgb", id);
-    updateTextField(trackName, conn, tableName, "chromStart", id);
-    updateTextField(trackName, conn, tableName, "chromEnd", id);
-    updateTextField(trackName, conn, tableName, "ref", id);
-    updateTextField(trackName, conn, tableName, "alt", id);
-    updateTextField(trackName, conn, tableName, "project", id);
-    updateTextField(trackName, conn, tableName, "mouseover", id);
+    /* Handle edits. Owner edits their own table, no project/db scope filter. */
+    updateTextField(trackName, conn, tableName, "name", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "description", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "itemRgb", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "chromStart", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "chromEnd", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "ref", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "alt", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "project", id, NULL, NULL);
+    updateTextField(trackName, conn, tableName, "mouseover", id, NULL, NULL);
     /* Update any custom fields */
         {
         char *editUserName = getUserName();
         struct slName *customCols = myVariantsGetCustomFields(editUserName);
         struct slName *col;
         for (col = customCols; col != NULL; col = col->next)
-            updateTextField(trackName, conn, tableName, col->name, id);
+            updateTextField(trackName, conn, tableName, col->name, id, NULL, NULL);
         slFreeList(&customCols);
         }
     /* Trigger CT refresh after edits */
     {
         char *userName = getUserName();
         if (userName)
             {
             char *ctFile = myVariantsWriteCtFile(userName, database, cart);
             if (isNotEmpty(ctFile))
                 {
                 char ctVar[256];
                 safef(ctVar, sizeof ctVar, CT_FILE_VAR_PREFIX "%s", database);
                 cartSetString(cart, ctVar, ctFile);
                 freeMem(ctFile);
                 }
             }
     }
     }
 }
 
 static struct linkedFeatures *loadMyVariantsItems(struct sqlConnection *conn,
     char *tableName, struct trackDb *tdb, char *whereExtra)
 /* Query tableName for myVariants items in the current window matching the
  * whereExtra clause (e.g. "db='hg38' and project='test'") and return them
  * as a linkedFeatures list. */
 {
 struct linkedFeatures *lf, *lfList = NULL;
 struct dyString *query = sqlDyStringCreate("select * from %s where ", tableName);
 hAddBinToQueryGeneral("bin", winStart, winEnd, query);
 sqlDyStringPrintf(query, " chrom='%s' and chromStart < %d and chromEnd > %d",
         chromName, winEnd, winStart);
 if (isNotEmpty(whereExtra))
     sqlDyStringPrintf(query, " and (%-s)", whereExtra);
 struct sqlResult *sr = sqlGetResult(conn, query->string);
 dyStringFree(&query);
 char **row;
 struct dyString *mouseover = dyStringNew(0);
 while ((row = sqlNextRow(sr)) != NULL)
     {
     struct myVariants *item = myVariantsLoad(row);
     struct bed *bed;
     AllocVar(bed);
     char buf[64];
     safef(buf, sizeof(buf), "%u %s", item->id, item->name);
     bed->chrom = item->chrom;
     bed->chromStart = item->chromStart;
     bed->chromEnd = item->chromEnd;
     bed->name = cloneString(buf);
     bed->score = item->score;
     bed->strand[0] = item->strand[0];
     bed->thickStart = item->thickStart;
     bed->thickEnd = item->thickEnd;
     bed->itemRgb = item->itemRgb;
     lf = bedMungToLinkedFeatures(&bed, tdb, 9, 0, 1000, TRUE);
     dyStringClear(mouseover);
     if (item->mouseover && isNotEmpty(item->mouseover))
         lf->mouseOver = cloneString(item->mouseover);
     else
         {
         dyStringPrintf(mouseover, "%s", buf);
         if (item->ref != NULL && isNotEmpty(item->ref))
             dyStringPrintf(mouseover, "<br>Ref: %s", item->ref);
         if (item->alt != NULL && isNotEmpty(item->alt))
             dyStringPrintf(mouseover, "<br>Alt: %s", item->alt);
         lf->mouseOver = cloneString(dyStringContents(mouseover));
         }
     slAddHead(&lfList, lf);
     }
 sqlFreeResult(&sr);
 dyStringFree(&mouseover);
 return lfList;
 }
 
 void myVariantsLoadItems(struct track *track)
 /* Load up items in track already.  Also make up a pseudo-item that is
  * where you drag to create an item. */
 {
 struct linkedFeatures *lfList = NULL;
 boolean isShared = startsWith("myVariants_shared_", track->track);
 
 if (isShared)
     {
-    /* Extract the token and look up the share info from the cart */
-    char *token = track->track + strlen("myVariants_shared_");
-    char cartVar[256];
-    safef(cartVar, sizeof(cartVar), MYVAR_SHARED_CART_PREFIX "%s", token);
-    char *cartVal = cartOptionalString(cart, cartVar);
-    if (isEmpty(cartVal))
+    /* Resolve via hgcentral so revoked/downgraded shares stop returning data. */
+    struct myVariantsShare *share = myVariantsResolveSharedTrack(track->track, cart);
+    if (share == NULL)
         return;
-    char *owner = NULL, *project = NULL, *db = NULL;
-    int permission = 0;
-    if (!myVariantsParseShareCartValue(cartVal, &owner, &project, &db, &permission, NULL))
+    /* Shared tracks are per-assembly; only load when the browser's current
+     * db matches the share's db. */
+    if (!sameString(share->db, database))
+        {
+        myVariantsShareFree(&share);
         return;
-    char *tableName = myVariantsGetDbTable(owner);
+        }
+    char *tableName = myVariantsGetDbTable(share->ownerUser);
     if (isEmpty(tableName))
         {
-        freeMem(owner);
-        freeMem(project);
-        freeMem(db);
+        myVariantsShareFree(&share);
         return;
         }
     struct sqlConnection *conn = hAllocConn(CUSTOM_TRASH);
-    struct dyString *whereClause = sqlDyStringCreate("db='%s'", database);
-    if (!sameString(project, "*"))
-        sqlDyStringPrintf(whereClause, " and project='%s'", project);
+    struct dyString *whereClause = sqlDyStringCreate("db='%s'", share->db);
+    if (!sameString(share->project, "*"))
+        sqlDyStringPrintf(whereClause, " and project='%s'", share->project);
     lfList = loadMyVariantsItems(conn, tableName, track->tdb,
         dyStringCannibalize(&whereClause));
     hFreeConn(&conn);
-    freeMem(owner);
-    freeMem(project);
-    freeMem(db);
+    myVariantsShareFree(&share);
     }
 else
     {
     /* Load user's own items */
     char *userName = getUserName();
     char *db = myVariantsGetDatabaseForUser(userName);
     if (!db)
         return;
     char *tableName = myVariantsGetDbTable(userName);
     struct sqlConnection *conn = hAllocConn(CUSTOM_TRASH);
     myVariantsEditOrDelete(track->track, conn, tableName);
     struct dyString *whereClause = sqlDyStringCreate("db='%s'", database);
     lfList = loadMyVariantsItems(conn, tableName, track->tdb,
         dyStringCannibalize(&whereClause));
     hFreeConn(&conn);
     }
 slReverse(&lfList);
 track->items = lfList;
 }
 
 char *myVariantsName(struct track *track, void *item)
 /* Return name of one of an item to display on left side. */
 {
 struct linkedFeatures *lf = item;
 char *name = lf->name;
 return name;
 }
 
 void myVariantsDrawLeftLabels(struct track *track, int seqStart, int seqEnd,
     struct hvGfx *hvg, int xOff, int yOff, int width, int height,
     boolean withCenterLabels, MgFont *font,
     Color color, enum trackVisibility vis)
 /* Draw left label - just in dense or full mode. Needed to cope with empty space at top of track. */
 {
 int y = yOff + myVariantsExtraHeight(track);
 int fontHeight = mgFontLineHeight(font);
 if (withCenterLabels)
     y += mgFontLineHeight(font);
 if (vis == tvDense)
     hvGfxTextRight(hvg, xOff, y, width-1, fontHeight, color, font, track->shortLabel);
 else if (vis == tvFull)
     {
     struct bed *bed, *bedList = track->items;
     for (bed = bedList; bed != NULL; bed = bed->next)
 	{
 	if (track->itemLabelColor != NULL)
 	    color = track->itemLabelColor(track, bed, hvg);
 	int itemHeight = track->itemHeight(track, bed);
 	hvGfxTextRight(hvg, xOff, y, width - 1,
 	    itemHeight, color, font, track->itemName(track, bed));
 	y += itemHeight;
 	}
     }
 /* In pack mode the draw routine takes care of the labels. */
 }
 
 
 int myVariantsTotalHeight(struct track *track, enum trackVisibility vis)
 /* Most fixed height track groups will use this to figure out the height
  * they use. */
 {
 track->height = tgFixedTotalHeightOptionalOverflow(track, vis, tl.fontHeight+1, tl.fontHeight, FALSE) + 
 	myVariantsExtraHeight(track);
 return track->height;
 }
 
 void myVariantsMethods(struct track *track)
 /* Set up special methods for myVariants type tracks. */
 {
 linkedFeaturesMethods(track);
 track->totalHeight = myVariantsTotalHeight;
 track->drawLeftLabels = myVariantsDrawLeftLabels;
 track->loadItems = myVariantsLoadItems;
 track->itemName = myVariantsName;
 track->nextItemButtonable = TRUE;
 }
 
 static void apiSuccess(struct jsonWrite *jw)
 /* Send 200 JSON response and exit. */
 {
 printf("Content-Type: application/json\n\n");
 puts(jw->dy->string);
 jsonWriteFree(&jw);
 exit(0);
 }
 
 static void apiError(int httpStatus, char *message)
 /* Send error JSON response with given HTTP status and exit. */
 {
 printf("Status: %d\n", httpStatus);
 printf("Content-Type: application/json\n\n");
 struct jsonWrite *jw = jsonWriteNew();
 jsonWriteObjectStart(jw, NULL);
 jsonWriteString(jw, "error", message);
 jsonWriteObjectEnd(jw);
 puts(jw->dy->string);
 jsonWriteFree(&jw);
 exit(0);
 }
 
 static void shareToJson(struct jsonWrite *jw, struct myVariantsShare *share)
 /* Write a single share record as a JSON object into jw. */
 {
 jsonWriteObjectStart(jw, NULL);
 jsonWriteNumber(jw, "id", share->id);
 jsonWriteString(jw, "ownerUser", share->ownerUser);
 jsonWriteString(jw, "shareToken", share->shareToken);
 jsonWriteString(jw, "project", share->project);
 jsonWriteString(jw, "db", share->db);
 jsonWriteNumber(jw, "permission", share->permission);
 jsonWriteString(jw, "targetUser", share->targetUser);
 jsonWriteString(jw, "label", share->label);
 jsonWriteString(jw, "createdAt", share->createdAt);
 jsonWriteObjectEnd(jw);
 }
 
 static boolean isStateChangingShareAction(char *action)
 /* Returns TRUE for actions that modify the share table.  Those require an
  * hgsid match to defend against CSRF; read-only actions don't, because the
  * response only goes to the originating cookie-bearing browser. */
 {
 return sameString(action, "createShare") || sameString(action, "revokeShare");
 }
 
 void myVariantsShareApiHandler(char *action)
 /* Handle share API requests. Outputs JSON to stdout and calls exit(0).
  * Called from main() before cartHtmlShell. */
 {
 char *userName = getUserName();
 if (userName == NULL)
     apiError(401, "not logged in");
 
 /* CSRF protection for state-changing actions: require the request to carry
  * an hgsid matching the user's session.  An attacker page can fire requests
  * with the user's cookies but cannot read or guess the session id, so this
  * blocks cross-site forgery of share creation/revocation. */
 if (isStateChangingShareAction(action))
     {
     char *suppliedHgsid = cgiOptionalString("hgsid");
     char *expectedHgsid = cartSessionId(cart);
     if (isEmpty(suppliedHgsid) || isEmpty(expectedHgsid)
         || !sameString(suppliedHgsid, expectedHgsid))
         apiError(403, "session token missing or invalid");
     }
 
 char *db = cgiOptionalString("db");
 if (db == NULL)
     apiError(400, "missing required parameter: db");
 
 struct sqlConnection *conn = hConnectCentral();
 
 if (!sqlTableExists(conn, "myVariantsShares"))
     {
     hDisconnectCentral(&conn);
     apiError(500, "myVariantsShares table not found - contact genome-www@ucsc.edu");
     }
 
 if (sameString(action, "createShare"))
     {
     char *project = cgiOptionalString("project");
     if (project == NULL)
         apiError(400, "missing required parameter: project");
     int permission = cgiOptionalInt("permission", MYVAR_PERM_READONLY);
     if (permission != MYVAR_PERM_READONLY && permission != MYVAR_PERM_READWRITE)
         apiError(400, "permission must be 0 or 1");
     char *targetUser = cgiOptionalString("targetUser");
     char *label = cgiOptionalString("label");
     /* Reject overlong fields before MySQL would (varchar(255)).  Use 200 to
      * leave room for any prefixing/quoting we add downstream. */
     if (strlen(project) > 200
         || (targetUser && strlen(targetUser) > 200)
         || (label && strlen(label) > 200))
         apiError(400, "project, targetUser, and label must each be <= 200 chars");
     /* Project must be "*" (all) or one of the owner's existing project values.
      * Prevents creating misleading share URLs that filter on a non-existent
      * project name. */
     if (!sameString(project, "*"))
         {
         struct slName *projects = myVariantsGetProjects(userName);
         boolean found = slNameInList(projects, project);
         slFreeList(&projects);
         if (!found)
             apiError(400, "project does not exist for current user");
         }
+    if (isNotEmpty(targetUser))
+        {
+        char gbq[512];
+        sqlSafef(gbq, sizeof(gbq),
+            "select count(*) from gbMembers where userName='%s'", targetUser);
+        if (sqlQuickNum(conn, gbq) == 0)
+            apiError(400, "targetUser not found - check the spelling, or omit"
+                " targetUser to make an 'anyone with link' share");
+        }
     struct myVariantsShare *share = myVariantsCreateShare(conn, userName,
         project, db, permission, targetUser, label);
     struct jsonWrite *jw = jsonWriteNew();
     jsonWriteObjectStart(jw, NULL);
     jsonWriteString(jw, "status", "ok");
     jsonWriteString(jw, "token", share->shareToken);
     jsonWriteNumber(jw, "id", share->id);
     jsonWriteObjectEnd(jw);
     myVariantsShareFree(&share);
     hDisconnectCentral(&conn);
     apiSuccess(jw);
     }
 else if (sameString(action, "getShares"))
     {
     struct myVariantsShare *shares = myVariantsGetSharesForOwner(conn, userName, db);
     struct jsonWrite *jw = jsonWriteNew();
     jsonWriteObjectStart(jw, NULL);
     jsonWriteString(jw, "status", "ok");
     jsonWriteListStart(jw, "shares");
     struct myVariantsShare *share;
     for (share = shares; share != NULL; share = share->next)
         shareToJson(jw, share);
     jsonWriteListEnd(jw);
     jsonWriteObjectEnd(jw);
     myVariantsShareFreeList(&shares);
     hDisconnectCentral(&conn);
     apiSuccess(jw);
     }
 else if (sameString(action, "getSharesForMe"))
     {
     struct myVariantsShare *shares = myVariantsGetSharesForUser(conn, userName, db);
     struct jsonWrite *jw = jsonWriteNew();
     jsonWriteObjectStart(jw, NULL);
     jsonWriteString(jw, "status", "ok");
     jsonWriteListStart(jw, "shares");
     struct myVariantsShare *share;
     for (share = shares; share != NULL; share = share->next)
         shareToJson(jw, share);
     jsonWriteListEnd(jw);
     jsonWriteObjectEnd(jw);
     myVariantsShareFreeList(&shares);
     hDisconnectCentral(&conn);
     apiSuccess(jw);
     }
 else if (sameString(action, "revokeShare"))
     {
     char *token = cgiOptionalString("shareToken");
     if (token == NULL)
         apiError(400, "missing required parameter: shareToken");
     boolean revoked = myVariantsRevokeShare(conn, token, userName);
     hDisconnectCentral(&conn);
     if (!revoked)
         apiError(404, "share not found");
     struct jsonWrite *jw = jsonWriteNew();
     jsonWriteObjectStart(jw, NULL);
     jsonWriteString(jw, "status", "ok");
     jsonWriteObjectEnd(jw);
     apiSuccess(jw);
     }
 else
     {
     hDisconnectCentral(&conn);
     apiError(400, "unknown action");
     }
 }
 
 void myVariantsProcessShareParam()
 /* Check for myVarShare CGI param, validate the share token, and store
  * the share reference in the cart. Must be called before track loading. */
 {
 char *token = cgiOptionalString(MYVAR_SHARE_CGI_VAR);
 if (isEmpty(token))
     return;
 
 if (strlen(token) != MYVAR_TOKEN_LENGTH)
     {
     notify("A share link in the URL couldn't be read. The shared track hasn't been added, but the rest of the browser works normally.", "myVarShareInvalidToken");
     return;
     }
 
 char *userName = getUserName();
 
 struct sqlConnection *conn = hConnectCentral();
 if (!sqlTableExists(conn, "myVariantsShares"))
     {
     hDisconnectCentral(&conn);
     return;
     }
 
 struct myVariantsShare *share = myVariantsGetShareByToken(conn, token);
 hDisconnectCentral(&conn);
 if (share == NULL)
     {
     notify("A share link is no longer valid (it may have been revoked). The shared track isn't available, but the rest of the browser works normally.", "myVarShareRevoked");
     return;
     }
 
 /* Targeted shares require the matching logged-in user. Shares with no targetUser
  * ("anyone with link") are accessible to anon users too. */
 if (isNotEmpty(share->targetUser))
     {
     if (userName == NULL)
         {
         notify("A shared track in this view is limited to a specific user. You can keep browsing.", "myVarShareNeedLogin");
         myVariantsShareFree(&share);
         return;
         }
     if (!sameString(share->targetUser, userName))
         {
         notify("A shared track in this view wasn't shared with your account. You can keep browsing; the track just won't appear.", "myVarShareWrongUser");
         myVariantsShareFree(&share);
         return;
         }
     }
 
 /* Store in cart so the shared track loader can find it during track loading */
 char cartVar[256];
 safef(cartVar, sizeof(cartVar), MYVAR_SHARED_CART_PREFIX "%s", token);
 char *cartVal = myVariantsShareCartValue(share);
 cartSetString(cart, cartVar, cartVal);
 freeMem(cartVal);
 myVariantsShareFree(&share);
 }
 
 void myVariantsProcessSharedEdits()
 /* Process pending edits for shared tracks before any track loading.
  * This ensures edits are committed to the database before both the
  * owner's track and the shared track query for items. */
 {
 /* Anon users cannot edit shared items, regardless of share permission. */
 char *userName = getUserName();
 if (userName == NULL)
     return;
 struct hashEl *shareVars = cartFindPrefix(cart, MYVAR_SHARED_CART_PREFIX);
 struct hashEl *el;
 for (el = shareVars; el != NULL; el = el->next)
     {
     char *token = el->name + strlen(MYVAR_SHARED_CART_PREFIX);
     char trackName[512];
     safef(trackName, sizeof(trackName), "myVariants_shared_%s", token);
 
     /* Check if there's a pending edit for this shared track */
     char varName[256];
     safef(varName, sizeof(varName), "%s_%s", trackName, "id");
     char *idString = cartOptionalString(cart, varName);
     if (idString == NULL)
         continue;
 
-    /* Re-validate the share against hgcentral on every edit. The cart-cached
-     * permission is not authoritative: the owner may have revoked the share
-     * or downgraded it from read-write to read-only since the recipient's
-     * cart was last set, and we don't want stale cart contents to grant
-     * writes that the live share record no longer permits. */
-    struct sqlConnection *centralConn = hConnectCentral();
-    if (!sqlTableExists(centralConn, "myVariantsShares"))
-        {
-        hDisconnectCentral(&centralConn);
-        continue;
-        }
-    struct myVariantsShare *liveShare = myVariantsGetShareByToken(centralConn, token);
-    hDisconnectCentral(&centralConn);
+    /* Revalidate via hgcentral so revoked/downgraded shares can't write. */
+    struct myVariantsShare *liveShare = myVariantsResolveSharedTrack(trackName, cart);
     if (liveShare == NULL)
         continue;
     if (liveShare->permission != MYVAR_PERM_READWRITE)
         {
         myVariantsShareFree(&liveShare);
         continue;
         }
-    if (isNotEmpty(liveShare->targetUser) && !sameString(liveShare->targetUser, userName))
-        {
-        myVariantsShareFree(&liveShare);
-        continue;
-        }
-    char *owner = cloneString(liveShare->ownerUser);
-    myVariantsShareFree(&liveShare);
-
-    char *tableName = myVariantsGetDbTable(owner);
+    char *tableName = myVariantsGetDbTable(liveShare->ownerUser);
     if (isEmpty(tableName))
         {
-        freeMem(owner);
+        myVariantsShareFree(&liveShare);
         continue;
         }
 
     int id = sqlUnsigned(idString);
     cartRemove(cart, varName);
 
     /* Handle cancel */
     safef(varName, sizeof(varName), "%s_%s", trackName, "cancel");
     if (cartVarExists(cart, varName))
         {
         cartRemove(cart, varName);
-        freeMem(owner);
+        myVariantsShareFree(&liveShare);
         continue;
         }
 
-    /* Apply field edits - no delete, no project change */
+    /* Apply field edits, scoped to the share's project/db so a recipient
+     * cannot edit rows in projects/assemblies they were not granted. */
+    char *sp = liveShare->project;
+    char *sd = liveShare->db;
     struct sqlConnection *conn = hAllocConn(CUSTOM_TRASH);
-    updateTextField(trackName, conn, tableName, "name", id);
-    updateTextField(trackName, conn, tableName, "description", id);
-    updateTextField(trackName, conn, tableName, "itemRgb", id);
-    updateTextField(trackName, conn, tableName, "chromStart", id);
-    updateTextField(trackName, conn, tableName, "chromEnd", id);
-    updateTextField(trackName, conn, tableName, "ref", id);
-    updateTextField(trackName, conn, tableName, "alt", id);
-    updateTextField(trackName, conn, tableName, "mouseover", id);
-    struct slName *customCols = myVariantsGetCustomFields(owner);
+    updateTextField(trackName, conn, tableName, "name", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "description", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "itemRgb", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "chromStart", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "chromEnd", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "ref", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "alt", id, sp, sd);
+    updateTextField(trackName, conn, tableName, "mouseover", id, sp, sd);
+    struct slName *customCols = myVariantsGetCustomFields(liveShare->ownerUser);
     struct slName *col;
     for (col = customCols; col != NULL; col = col->next)
-        updateTextField(trackName, conn, tableName, col->name, id);
+        updateTextField(trackName, conn, tableName, col->name, id, sp, sd);
     slFreeList(&customCols);
     hFreeConn(&conn);
-    freeMem(owner);
+    myVariantsShareFree(&liveShare);
     }
 hashElFreeList(&shareVars);
 }
 
 boolean myVariantsTrackEnabled()
 /* Return TRUE if the "My Variants" feature is enabled in hg.conf
  * and the current request comes from a valid user */
 {
 return cfgOptionBooleanDefault("doMyVariants", FALSE) && (getUserName() != NULL);
 }