Fix CreateLink operation destination string formatting on Windows

- Fix string formatting syntax in createJunction() method.
- Calculate destination directory string length in bytes rather than
  characters count.
- Make minor alterations to operation usage documentation.

Task-number: QTIFW-1443
Change-Id: Ia7f6525c865a3e8a6da5376059111c1ef87353ac
Reviewed-by: Katja Marttila <katja.marttila@qt.io>

2 files changed, 9 insertions, 6 deletions

diff --git a/doc/operations.qdoc b/doc/operations.qdoc
index 98906ab9c..762d12330 100644
--- a/doc/operations.qdoc
+++ b/doc/operations.qdoc
@@ -205,8 +205,8 @@
         \row
             \li CreateLink
             \li "CreateLink" \c linkPath \c targetPath
-            \li Creates a link from the location specified by \c linkPath to
-                the location specified by \c targetPath.
+            \li Creates a link in the location specified by \c linkPath that
+                points to the location specified by \c targetPath.
         \row
             \li CreateLocalRepository
             \li "CreateLocalRepository" \c binaryPath \c repoPath
diff --git a/src/libs/installer/link.cpp b/src/libs/installer/link.cpp
index 62ba06cb2..0c79ec4c9 100644
--- a/src/libs/installer/link.cpp
+++ b/src/libs/installer/link.cpp
@@ -146,9 +146,12 @@ Link createJunction(const QString &linkPath, const QString &targetPath)
         return Link(linkPath);
     }
 
-    const QString szDestDir = QString::fromLatin1("\\??\\").arg(targetPath).replace(QLatin1Char('/'),
+    const QString szDestDir = QString::fromLatin1("\\??\\%1").arg(targetPath).replace(QLatin1Char('/'),
         QLatin1Char('\\'));
 
+    // Get string length in bytes, not in characters count
+    const size_t destDirBytes = szDestDir.size() * sizeof(ushort);
+
     // Allocates a block of memory for an array of num elements(1) and initializes all its bits to zero.
     REPARSE_DATA_BUFFER* reparseStructData = (REPARSE_DATA_BUFFER*)calloc(1,
         MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
@@ -156,11 +159,11 @@ Link createJunction(const QString &linkPath, const QString &targetPath)
     reparseStructData->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
     reparseStructData->MountPointReparseBuffer.PrintNameLength = 0;
     reparseStructData->MountPointReparseBuffer.SubstituteNameOffset = 0;
-    reparseStructData->MountPointReparseBuffer.SubstituteNameLength = szDestDir.length();
-    reparseStructData->MountPointReparseBuffer.PrintNameOffset = szDestDir.length() + sizeof(WCHAR);
+    reparseStructData->MountPointReparseBuffer.SubstituteNameLength = destDirBytes;
+    reparseStructData->MountPointReparseBuffer.PrintNameOffset = destDirBytes + sizeof(WCHAR);
 
     uint spaceAfterGeneralData = sizeof(USHORT) * 5 + sizeof(WCHAR); //should be 12
-    reparseStructData->ReparseDataLength = szDestDir.length() + spaceAfterGeneralData;
+    reparseStructData->ReparseDataLength = destDirBytes + spaceAfterGeneralData;
 
 #ifndef Q_CC_MINGW
     StringCchCopy(reparseStructData->MountPointReparseBuffer.PathBuffer, 1024, (wchar_t*)szDestDir.utf16());