Fix bug 11346

Enclose in braces an optional argument of a math macro when it
starts with an incomplete script inset or ends with a delimiter
size-modifier macro.

diff --git a/src/mathed/InsetMathMacro.cpp b/src/mathed/InsetMathMacro.cpp
index 668562899dedf32aec578efd9202f60fd2421369..f37b73b9635df1652931ac5022c4e06cbb29c0c3 100644 (file)
--- a/src/mathed/InsetMathMacro.cpp
+++ b/src/mathed/InsetMathMacro.cpp
@@ -15,6 +15,7 @@
 #include "InsetMathMacro.h"
 
 #include "InsetMathChar.h"
+#include "InsetMathScript.h"
 #include "MathCompletionList.h"
 #include "MathExtern.h"
 #include "MathFactory.h"
@@ -1106,7 +1107,22 @@ void InsetMathMacro::write(WriteStream & os) const
        // print out optionals
        for (i=0; i < cells_.size() && i < emptyOptFrom; ++i) {
                first = false;
-               os << "[" << cell(i) << "]";
+               // For correctly parsing it when a document is reloaded, we
+               // need to enclose an optional argument in braces if it starts
+               // with a script inset with empty nucleus or ends with a
+               // delimiter-size-modifier macro (see #10497 and #11346)
+               bool braced = false;
+               size_type last = cell(i).size() - 1;
+               if (cell(i)[last].nucleus()->asUnknownInset()) {
+                       latexkeys const * l = in_word_set(cell(i)[last].nucleus()->name());
+                       braced = (l && l->inset == "big");
+               } else if (cell(i)[0].nucleus()->asScriptInset()) {
+                       braced = cell(i)[0].nucleus()->asScriptInset()->nuc().empty();
+               }
+               if (braced)
+                       os << "[{" << cell(i) << "}]";
+               else
+                       os << "[" << cell(i) << "]";
        }
 
        // skip the tailing empty optionals