Fix dataloss for align env inside math

The math parser aborts with an error message on \begin{align} and
\begin{align*} if this is not the hull inset. This is now fixed, however
this is not complete support for these two environments (the GUI does not
respect the numbering). It is only the minimal fix that ensures that no data
loss occurs for documents imported by tex2lyx.

src/mathed/InsetMathSplit.cpp

@@ -32,9 +32,12 @@ namespace lyx {
 using support::bformat;
 
 
+// FIXME: handle numbers in gui, currently they are only read and written
+
 InsetMathSplit::InsetMathSplit(Buffer * buf, docstring const & name,
-	char valign)
-	: InsetMathGrid(buf, 1, 1, valign, docstring()), name_(name)
+	char valign, bool numbered)
+	: InsetMathGrid(buf, 1, 1, valign, docstring()), name_(name),
+	  numbered_(numbered)
 {
 }
 
@@ -51,7 +54,7 @@ char InsetMathSplit::defaultColAlign(col_type col)
 		return 'l';
 	if (name_ == "gathered")
 		return 'c';
-	if (name_ == "aligned")
+	if (name_ == "aligned" || name_ == "align")
 		return (col & 1) ? 'l' : 'r';
 	if (name_ == "alignedat")
 		return (col & 1) ? 'l' : 'r';
@@ -97,15 +100,18 @@ void InsetMathSplit::write(WriteStream & ws) const
 	MathEnsurer ensurer(ws);
 	if (ws.fragile())
 		ws << "\\protect";
-	ws << "\\begin{" << name_ << '}';
-	if (name_ != "split" && verticalAlignment() != 'c')
+	docstring suffix;
+	if (!numbered_ && name_ == "align")
+		suffix = from_ascii("*");
+	ws << "\\begin{" << name_ << suffix << '}';
+	if (name_ != "split" && name_ != "align" && verticalAlignment() != 'c')
 		ws << '[' << verticalAlignment() << ']';
 	if (name_ == "alignedat")
 		ws << '{' << static_cast<unsigned int>((ncols() + 1)/2) << '}';
 	InsetMathGrid::write(ws);
 	if (ws.fragile())
 		ws << "\\protect";
-	ws << "\\end{" << name_ << "}\n";
+	ws << "\\end{" << name_ << suffix << "}\n";
 }
 
 
@@ -113,6 +119,9 @@ void InsetMathSplit::infoize(odocstream & os) const
 {
 	docstring name = name_;
 	name[0] = support::uppercase(name[0]);
+	if (name_ == "align" && !numbered_)
+		os << name << "* ";
+	else
 		os << name << ' ';
 }
 
@@ -127,6 +136,7 @@ void InsetMathSplit::mathmlize(MathStream & ms) const
 	// it's not clear how to do that without copying a lot of code.
 	// One idea would be to wrap the table in an <mrow>, and set the
 	// alignment there via CSS.
+	// FIXME how to handle numbered and unnumbered align?
 	InsetMathGrid::mathmlize(ms);
 }
 
@@ -138,6 +148,7 @@ void InsetMathSplit::htmlize(HtmlStream & ms) const
 	// special treatment.
 	// FIXME
 	// lgathered and rgathered could use the proper alignment.
+	// FIXME how to handle numbered and unnumbered align?
 	InsetMathGrid::htmlize(ms);
 }
 
@@ -145,7 +156,7 @@ void InsetMathSplit::htmlize(HtmlStream & ms) const
 void InsetMathSplit::validate(LaTeXFeatures & features) const
 {
 	if (name_ == "split" || name_ == "gathered" || name_ == "aligned" ||
-	    name_ == "alignedat")
+	    name_ == "alignedat" || name_ == "align")
 		features.require("amsmath");
 	else if (name_ == "lgathered" || name_ == "rgathered")
 		features.require("mathtools");

src/mathed/InsetMathSplit.h

@@ -22,7 +22,7 @@ class InsetMathSplit : public InsetMathGrid {
 public:
 	///
 	explicit InsetMathSplit(Buffer * buf, docstring const & name,
-		char valign = 'c');
+		char valign = 'c', bool numbered = false);
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
@@ -50,6 +50,8 @@ private:
 	virtual Inset * clone() const;
 	///
 	docstring name_;
+	///
+	bool numbered_;
 };
 
 

src/mathed/MathParser.cpp

@@ -1603,14 +1603,14 @@ bool Parser::parse1(InsetMathGrid & grid, unsigned flags,
 			}
 
 			else if (name == "align" || name == "align*") {
-				if (mode != InsetMath::UNDECIDED_MODE) {
-					// FIXME this is wrong: amsmath supports
-					//       align* inside gather, see testmath.tex.
-					error("bad math environment " + name);
-					break;
-				}
+				if (mode == InsetMath::UNDECIDED_MODE) {
 					cell->push_back(MathAtom(new InsetMathHull(buf, hullAlign)));
 					parse2(cell->back(), FLAG_END, InsetMath::MATH_MODE, !stared(name));
+				} else {
+					cell->push_back(MathAtom(new InsetMathSplit(buf, name,
+							'c', !stared(name))));
+					parse2(cell->back(), FLAG_END, mode, !stared(name));
+				}
 			}
 
 			else if (name == "flalign" || name == "flalign*") {