Check whether the buffer pointer is valid before using it

diff --git a/src/mathed/MathMacro.cpp b/src/mathed/MathMacro.cpp
index 636d059a23a25ecf0090683ee91254ac29c71332..78ea2bb3654913789464948ac5efeb8a89684fec 100644 (file)
--- a/src/mathed/MathMacro.cpp
+++ b/src/mathed/MathMacro.cpp
@@ -207,7 +207,7 @@ MathMacro::MathMacro(MathMacro const & that)
                // We need to update d->macro_ by ourselves because in this case
                // MathData::metrics() is not called when selecting a math inset
                DocIterator const & pos = d->macroBackup_.pos();
-               d->macro_ = pos.buffer()->getMacro(name(), pos);
+               d->macro_ = pos.buffer() ? pos.buffer()->getMacro(name(), pos) : 0;
                if (!d->macro_)
                        d->macro_ = &d->macroBackup_;
        }
@@ -225,7 +225,7 @@ MathMacro & MathMacro::operator=(MathMacro const & that)
                // We need to update d->macro_ by ourselves because in this case
                // MathData::metrics() is not called when selecting a math inset
                DocIterator const & pos = d->macroBackup_.pos();
-               d->macro_ = pos.buffer()->getMacro(name(), pos);
+               d->macro_ = pos.buffer() ? pos.buffer()->getMacro(name(), pos) : 0;
                if (!d->macro_)
                        d->macro_ = &d->macroBackup_;
        }