QZipReader: update to unzip partly broken archives

The problem was discovered while providing a fix for the linked issue.
The original zip archive is very old, and it does not contain separate
entries for directories, only for files.
As a result, QZipReader algorithm was failing to create all the
necessary subdirectory structures, and unzipping failed.

This patch detects such case, and creates a directory hierarchy based
on the file paths.

Task-number: QTBUG-81503
Pick-to: 6.3 6.2 5.15
Change-Id: I204f9b620853b3ffcbb9cbf6fe08fb5958776ea0
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/gui/text/qzip.cpp b/src/gui/text/qzip.cpp
index 711482af8a..1fe7a6d042 100644
--- a/src/gui/text/qzip.cpp
+++ b/src/gui/text/qzip.cpp
@@ -1024,13 +1024,33 @@ bool QZipReader::extractAll(const QString &destinationDir) const
 
     // create directories first
     const QList<FileInfo> allFiles = fileInfoList();
+    bool foundDirs = false;
+    bool hasDirs = false;
     for (const FileInfo &fi : allFiles) {
         const QString absPath = destinationDir + QDir::separator() + fi.filePath;
         if (fi.isDir) {
+            foundDirs = true;
             if (!baseDir.mkpath(fi.filePath))
                 return false;
             if (!QFile::setPermissions(absPath, fi.permissions))
                 return false;
+        } else if (!hasDirs && fi.filePath.contains(u"/")) {
+            // filePath does not have leading or trailing '/', so if we find
+            // one, than the file path contains directories.
+            hasDirs = true;
+        }
+    }
+
+    // Some zip archives can be broken in the sense that they do not report
+    // separate entries for directories, only for files. In this case we
+    // need to recreate directory structure based on the file paths.
+    if (hasDirs && !foundDirs) {
+        for (const FileInfo &fi : allFiles) {
+            const auto dirPath = fi.filePath.left(fi.filePath.lastIndexOf(u"/"));
+            if (!baseDir.mkpath(dirPath))
+                return false;
+            // We will leave the directory permissions default in this case,
+            // because setting dir permissions based on file is incorrect
         }
     }