From b0d395e27c7bbc6ee34a12ec07426581e013be08 Mon Sep 17 00:00:00 2001
From: Vladimir Belyavsky <belyavskyv@gmail.com>
Date: Fri, 17 Feb 2023 19:31:50 +0300
Subject: [PATCH] Text: fix Soft hyphen rendering in QTextLayout::glyphRuns()

When calculating the position offset of QGlyphRuns, either
when fetching substrings or when applying fallback fonts,
we would include the advances of non-printable glyphs,
such as the soft hyphen. This was an oversight, and the
other code which calculates the advance (like in
QFontEngine::getGlyphPositions()) does this correctly. We
apply the same logic as there and only include the advance
if the dontPrint flag is unset.

[ChangeLog][QtGui][Text] Fixed an issue where spaces would
sometimes be shown in soft hyphen positions in a string.

Fixes: QTBUG-46990
Fixes: QTBUG-62620
Fixes: QTBUG-67038
Fixes: QTBUG-102483
Change-Id: I4e583fb74f7a51424f14917d7cc0894beefec48b
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit 0fe6f818d23495f07100f82c12e4232b8e56daf4)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/gui/text/qtextlayout.cpp | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 752c6180f8d..486e04544af 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -2492,14 +2492,18 @@ QList<QGlyphRun> QTextLine::glyphRuns(int from,
         // when we're breaking a RTL script item, since the expected position passed into
         // getGlyphPositions() is the left-most edge of the left-most glyph in an RTL run.
         if (relativeFrom != (iterator.itemStart - si.position) && !rtl) {
-            for (int i=itemGlyphsStart; i<glyphsStart; ++i) {
-                QFixed justification = QFixed::fromFixed(glyphLayout.justifications[i].space_18d6);
-                pos.rx() += (glyphLayout.advances[i] + justification).toReal();
+            for (int i = itemGlyphsStart; i < glyphsStart; ++i) {
+                if (!glyphLayout.attributes[i].dontPrint) {
+                    QFixed justification = QFixed::fromFixed(glyphLayout.justifications[i].space_18d6);
+                    pos.rx() += (glyphLayout.advances[i] + justification).toReal();
+                }
             }
         } else if (relativeTo != (iterator.itemEnd - si.position - 1) && rtl) {
-            for (int i=itemGlyphsEnd; i>glyphsEnd; --i) {
-                QFixed justification = QFixed::fromFixed(glyphLayout.justifications[i].space_18d6);
-                pos.rx() += (glyphLayout.advances[i] + justification).toReal();
+            for (int i = itemGlyphsEnd; i > glyphsEnd; --i) {
+                if (!glyphLayout.attributes[i].dontPrint) {
+                    QFixed justification = QFixed::fromFixed(glyphLayout.justifications[i].space_18d6);
+                    pos.rx() += (glyphLayout.advances[i] + justification).toReal();
+                }
             }
         }
 
@@ -2554,8 +2558,10 @@ QList<QGlyphRun> QTextLine::glyphRuns(int from,
                             glyphRuns.append(glyphRun);
                     }
                     for (int i = 0; i < subLayout.numGlyphs; ++i) {
-                        QFixed justification = QFixed::fromFixed(subLayout.justifications[i].space_18d6);
-                        pos.rx() += (subLayout.advances[i] + justification).toReal();
+                        if (!subLayout.attributes[i].dontPrint) {
+                            QFixed justification = QFixed::fromFixed(subLayout.justifications[i].space_18d6);
+                            pos.rx() += (subLayout.advances[i] + justification).toReal();
+                        }
                     }
 
                     if (rtl)