fix a crash after row drag between cols

Author: jcupitt

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - better change handling in ientry improves matrixview behaviour
 - better subrow finding fixes replace from file in nested columns
+- fix a crash on row access after row drag between columns
 
 ## 9.0.4 2025/03/20
 

TODO

@@ -1,10 +1,3 @@
-- try
-
-	nip4 ~/lady_orig.ws
-	drag A2 into column I
-	press V (down) on A2, segv
-
-
 - "reset" in display bar resets the position of scale/offset widgets, but does
   not reset the menu items (eg. tick on falsecolour)
 

src/icontainer.c

@@ -431,8 +431,9 @@ icontainer_current(iContainer *parent, iContainer *child)
 
 #ifdef DEBUG
 	printf("icontainer_current: (child %p)\n", child);
-	printf("\tchild: %s \"%s\"\n",
-		G_OBJECT_TYPE_NAME(child), IOBJECT(child)->name);
+	if (child)
+		printf("\tchild: %s \"%s\"\n",
+			G_OBJECT_TYPE_NAME(child), IOBJECT(child)->name);
 #endif /*DEBUG*/
 
 #ifdef DEBUG_SANITY

src/reduce.c

@@ -2112,9 +2112,11 @@ reduce_regenerate_member(Expr *expr, PElement *ths, PElement *out)
 	 */
 	if (is_super(expr->compile->sym)) {
 		Compile *parent = compile_get_parent(expr->compile);
+		Subcolumn *scol = row_get_subcolumn(expr->row);
+
 		PElement instance;
 
-		PEPOINTE(&instance, &expr->row->scol->base);
+		PEPOINTE(&instance, &scol->base);
 
 		if (!class_new_super(heap, parent, ths, &instance))
 			return FALSE;

src/row.c

@@ -563,7 +563,7 @@ row_child_add(iContainer *parent, iContainer *child, int pos)
 	row->child_rhs = row_get_rhs(row);
 }
 
-static Subcolumn *
+Subcolumn *
 row_get_subcolumn(Row *row)
 {
 	return SUBCOLUMN(ICONTAINER(row)->parent);
@@ -607,7 +607,6 @@ row_parent_add(iContainer *child)
 
 	/* Update our context.
 	 */
-	row->scol = row_get_subcolumn(row);
 	row->ws = row_get_workspace(row);
 	row->top_row = row_get_root(row);
 }
@@ -623,7 +622,6 @@ row_parent_remove(iContainer *child)
 	row_deselect(row);
 	workspace_queue_layout(row->ws);
 
-	row->scol = NULL;
 	row->ws = NULL;
 	row->top_row = NULL;
 
@@ -785,14 +783,16 @@ row_set_to_save(Row *row)
 	Row *enclosing;
 
 	if (!row->to_save) {
+		Subcolumn *scol = row_get_subcolumn(row);
+
 		row->to_save = TRUE;
 
 		/* All peers must be saved. When we reload, we want to keep
 		 * row ordering. If we just save modded row, they'll move to
 		 * the front of the row list on reload, since they'll be made
 		 * first.
 		 */
-		icontainer_map(ICONTAINER(row->scol),
+		icontainer_map(ICONTAINER(scol),
 			(icontainer_map_fn) row_set_to_save, NULL, NULL);
 
 		/* All rows back up to the top level must also be saved.
@@ -984,7 +984,6 @@ row_init(Row *row)
 	printf("row_init:\n");
 #endif /*DEBUG*/
 
-	row->scol = NULL;
 	row->child_rhs = NULL;
 	row->ws = NULL;
 	row->top_row = NULL;
@@ -1177,6 +1176,8 @@ row_link_build2(Expr *expr, Row *row)
 static void *
 row_link_build(Row *row)
 {
+	Subcolumn *scol = row_get_subcolumn(row);
+
 #ifdef DEBUG_LINK
 	printf("row_link_build: ");
 	row_name_print(row);
@@ -1185,7 +1186,7 @@ row_link_build(Row *row)
 
 	/* Build new recomp list. Only for class displays.
 	 */
-	if (!row->scol->is_top && row->expr &&
+	if (!scol->is_top && row->expr &&
 		row_link_build2(row->expr, row))
 		return row;
 
@@ -1502,11 +1503,11 @@ row_regenerate(Row *row)
 				 * local classes); the enclosing one should
 				 * be the same as the most enclosing this.
 				 */
-				Row *this = row->scol->this;
+				Subcolumn *scol = row_get_subcolumn(row);
+				Row *this = scol->this;
 				gboolean res;
 
-				res = reduce_regenerate_member(expr,
-					&this->expr->root, root);
+				res = reduce_regenerate_member(expr, &this->expr->root, root);
 				expr_new_value(expr);
 
 				if (!res)
@@ -1528,6 +1529,7 @@ static gboolean
 row_recomp_row(Row *row)
 {
 	Rhs *rhs = row->child_rhs;
+	Subcolumn *scol = row_get_subcolumn(row);
 
 #ifdef DEBUG
 	printf("row_recomp_row: ");
@@ -1553,7 +1555,7 @@ row_recomp_row(Row *row)
 	/* We're about to zap the graph: make sure this tree of rows has a
 	 * private copy.
 	 */
-	if (!subcolumn_make_private(row->scol))
+	if (!subcolumn_make_private(scol))
 		return FALSE;
 
 	/* Regenerate from the expr.
@@ -1873,8 +1875,9 @@ row_select_extend(Row *row)
 	/* Range select if there was a previous selection, and it was in the
 	 * same subcolumn.
 	 */
-	if (last_select && row->scol == last_select->scol) {
-		Subcolumn *scol = row->scol;
+	if (last_select &&
+		row_get_subcolumn(row) == row_get_subcolumn(last_select)) {
+		Subcolumn *scol = row_get_subcolumn(row);
 		GSList *rows = ICONTAINER(scol)->children;
 		int pos = g_slist_index(rows, row);
 		int pos_last = g_slist_index(rows, last_select);

src/row.h

@@ -52,7 +52,6 @@ struct _Row {
 
 	/* Our context.
 	 */
-	Subcolumn *scol; /* Enclosing subcolumn */
 	Rhs *child_rhs;	 /* Child RHS */
 	Workspace *ws;	 /* Enclosing workspace */
 	Row *top_row;	 /* Enclosing root row */
@@ -89,6 +88,7 @@ const char *row_name(Row *row);
 void row_qualified_name_relative(Symbol *context, Row *row, VipsBuf *buf);
 void row_qualified_name(Row *row, VipsBuf *buf);
 void *row_name_print(Row *row);
+Subcolumn *row_get_subcolumn(Row *row);
 Column *row_get_column(Row *row);
 
 void row_error_set(Row *row);

src/subcolumn.c

@@ -430,7 +430,7 @@ subcolumn_get_subcolumn(Subcolumn *scol)
 		Rhs *rhs = HEAPMODEL(scol)->rhs;
 		Row *row = HEAPMODEL(rhs)->row;
 
-		return row->scol;
+		return row_get_subcolumn(row);
 	}
 }
 
@@ -445,7 +445,8 @@ subcolumn_get_root_subcolumn(Subcolumn *scol)
 	else {
 		Subcolumn *enclosing = subcolumn_get_subcolumn(scol);
 
-		return enclosing->is_top ? scol : subcolumn_get_root_subcolumn(enclosing);
+		return enclosing->is_top ?
+			scol : subcolumn_get_root_subcolumn(enclosing);
 	}
 }
 
@@ -454,7 +455,8 @@ subcolumn_get_root_subcolumn(Subcolumn *scol)
 Column *
 subcolumn_get_column(Subcolumn *scol)
 {
-	Subcolumn *root = scol->is_top ? scol : subcolumn_get_subcolumn(subcolumn_get_root_subcolumn(scol));
+	Subcolumn *root = scol->is_top ?
+		scol : subcolumn_get_subcolumn(subcolumn_get_root_subcolumn(scol));
 
 	return COLUMN(ICONTAINER(root)->parent);
 }