QListView: Prevent infinite loop when wrapping text of item with null-icon

If an item in a list view has a null icon, then the decorationSize gets
calculated as -1, -1. The style would then try to wrap the text to a
lineWidth of -1, ending up in an infinite loop in viewItemTextLayout.

To prevent that, don't set the HasDecoration flag of the style option
when the icon is null, and don't fall back ot the decorationSize unless
the flag is set.

Add a test for this particular item configuration. This also fixes the
widget baseline test with styles that don't provide all standard icons.

Pick-to: 6.5
Change-Id: I691db6abede9a9b2ad300f3ee7fbfdae5fb6097f
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Santhosh Kumar <santhosh.kumar.selvaraj@qt.io>

1 files changed, 14 insertions, 5 deletions

diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index c7dee0549e..1af0038dc2 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -941,12 +941,21 @@ QSize QCommonStylePrivate::viewItemSize(const QStyleOptionViewItem *option, int
                 break;
             }
             case QStyleOptionViewItem::Top:
-            case QStyleOptionViewItem::Bottom:
-                if (wrapText)
-                    bounds.setWidth(bounds.isValid() ? bounds.width() - 2 * textMargin : option->decorationSize.width());
-                else
-                    bounds.setWidth(QFIXED_MAX);
+            case QStyleOptionViewItem::Bottom: {
+                int width;
+                if (wrapText) {
+                    if (bounds.isValid())
+                        width = bounds.width() - 2 * textMargin;
+                    else if (option->features & QStyleOptionViewItem::HasDecoration)
+                        width = option->decorationSize.width();
+                    else
+                        width = 0;
+                } else {
+                    width = QFIXED_MAX;
+                }
+                bounds.setWidth(width);
                 break;
+            }
             default:
                 break;
             }