QFormLayout: Fix width calculation when a row has no label

The calculation of the minimum width assumes that when there is no label
for a row, the field occupies the full row. But this is only true when
QFormLayout::SpanningRole is set for this row. This lead to a to small
minimum size for the row / truncated widgets when the row in question is
the longest one in the form layout.
Fix it by checking if it is a spanned row instead if there is not label
when calculating the sizes.

Fixes: QTBUG-18308
Fixes: QTBUG-60800
Change-Id: I1a610c93ab5c7f9cac503721ae99b36f2710c634
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 6 insertions, 4 deletions

diff --git a/src/widgets/kernel/qformlayout.cpp b/src/widgets/kernel/qformlayout.cpp
index 66e8858e21..101ce8b64c 100644
--- a/src/widgets/kernel/qformlayout.cpp
+++ b/src/widgets/kernel/qformlayout.cpp
@@ -419,13 +419,15 @@ void QFormLayoutPrivate::updateSizes()
             if (label) {
                 maxMinLblWidth = qMax(maxMinLblWidth, label->minSize.width());
                 maxShLblWidth = qMax(maxShLblWidth, label->sizeHint.width());
-                if (field) {
+            }
+            if (field) {
+                if (field->fullRow) {
+                    maxMinIfldWidth = qMax(maxMinIfldWidth, field->minSize.width());
+                    maxShIfldWidth = qMax(maxShIfldWidth, field->sizeHint.width());
+                } else {
                     maxMinFldWidth = qMax(maxMinFldWidth, field->minSize.width() + field->sbsHSpace);
                     maxShFldWidth = qMax(maxShFldWidth, field->sizeHint.width() + field->sbsHSpace);
                 }
-            } else if (field) {
-                maxMinIfldWidth = qMax(maxMinIfldWidth, field->minSize.width());
-                maxShIfldWidth = qMax(maxShIfldWidth, field->sizeHint.width());
             }
 
             prevLbl = label;