[Libreoffice-commits] core.git: include/o3tl vcl/source

[Stephan Bergmann (via logerrit)]

 include/o3tl/restoreguard.hxx |   40 ++++++++++++++++++++++++++++++++++++++++
 vcl/source/fontsubset/cff.cxx |    7 +++----
 2 files changed, 43 insertions(+), 4 deletions(-)

New commits:
commit 2469c623d7985e9e5db54ed8f96df02219def74d
Author:     Stephan Bergmann <sberg...@redhat.com>
AuthorDate: Mon Nov 7 10:58:08 2022 +0100
Commit:     Stephan Bergmann <sberg...@redhat.com>
CommitDate: Tue Nov 8 07:14:21 2022 +0100

    Introduce o3tl::RestoreGuard
    
    Change-Id: Ic0c1a73668e990c91ef6e90e8c01e669761fe356
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/142403
    Tested-by: Jenkins
    Reviewed-by: Stephan Bergmann <sberg...@redhat.com>

diff --git a/include/o3tl/restoreguard.hxx b/include/o3tl/restoreguard.hxx
new file mode 100644
index 000000000000..19075be3dcea
--- /dev/null
+++ b/include/o3tl/restoreguard.hxx
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; 
fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <sal/config.h>
+
+// A convenience guard class that captures a given object's value on guard 
construction and restores
+// it on guard destruction:
+namespace o3tl
+{
+template <typename T> class RestoreGuard
+{
+public:
+    RestoreGuard(T& object)
+        : object_(object)
+        , value_(object)
+    {
+    }
+
+    ~RestoreGuard() { object_ = value_; }
+
+private:
+    RestoreGuard(RestoreGuard&) = delete;
+    RestoreGuard(RestoreGuard&&) = delete;
+    void operator=(RestoreGuard&) = delete;
+    void operator=(RestoreGuard&&) = delete;
+
+    T& object_;
+    T value_;
+};
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s 
cinkeys+=0=break: */
diff --git a/vcl/source/fontsubset/cff.cxx b/vcl/source/fontsubset/cff.cxx
index 6d1cac5040b5..c398ccb18b98 100644
--- a/vcl/source/fontsubset/cff.cxx
+++ b/vcl/source/fontsubset/cff.cxx
@@ -24,6 +24,7 @@
 
 #include <fontsubset.hxx>
 
+#include <o3tl/restoreguard.hxx>
 #include <o3tl/safeint.hxx>
 #include <strhelper.hxx>
 #include <sal/log.hxx>
@@ -1541,8 +1542,8 @@ const char* CffSubsetterContext::getString( int nStringID)
         return pStringIds[ nStringID];
 
     // else get the string from the StringIndex table
-    const U8* pReadPtr = mpReadPtr;
-    const U8* pReadEnd = mpReadEnd;
+    o3tl::RestoreGuard pReadPtr(mpReadPtr);
+    o3tl::RestoreGuard pReadEnd(mpReadEnd);
     nStringID -= nStdStrings;
     int nLen = seekIndexData( mnStringIdxBase, nStringID);
     // assert( nLen >= 0);
@@ -1559,8 +1560,6 @@ const char* CffSubsetterContext::getString( int nStringID)
             aNameBuf[i] = *(mpReadPtr++);
         aNameBuf[ nLen] = '\0';
     }
-    mpReadPtr = pReadPtr;
-    mpReadEnd = pReadEnd;
     return aNameBuf;
 }