Fix crash due to recursive function call when a counter references itself.

e.g.:

Counter
    Name                 Version
    LabelString          "\theVersion.0"
End


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@23166 a592a061-630c-0410-9148-cb99ea01b6c8

src/Counters.cpp

@@ -339,10 +339,23 @@ docstring Counters::labelItem(docstring const & ctr,
 
 
 docstring Counters::theCounter(docstring const & counter)
+{
+	std::set<docstring> callers;
+	return theCounter(counter, callers);
+}
+
+docstring Counters::theCounter(docstring const & counter,
+                               std::set<docstring> & callers)
 {
 	if (!hasCounter(counter))
 		return from_ascii("??");
 
+	docstring label;
+
+	if (callers.find(counter) == callers.end()) {
+		
+		pair<std::set<docstring>::iterator, bool> result = callers.insert(counter);
+
 		Counter const & c = counterList[counter];
 		docstring ls = appendix() ? c.labelStringAppendix() : c.labelString();
 
@@ -351,11 +364,23 @@ docstring Counters::theCounter(docstring const & counter)
 				ls = from_ascii("\\the") + c.master() + from_ascii(".");
 			ls += from_ascii("\\arabic{") + counter + "}";
 		}
-	return counterLabel(ls);
+
+		label = counterLabel(ls, &callers);
+
+		callers.erase(result.first);
+	} else {
+		// recursion detected
+		lyxerr << "Warning: Recursion in label for counter `"
+			   << counter << "' detected"
+			   << endl;
+	}
+
+	return label;
 }
 
 
-docstring Counters::counterLabel(docstring const & format)
+docstring Counters::counterLabel(docstring const & format,
+                                 std::set<docstring> * callers)
 {
 	docstring label = format;
 
@@ -373,7 +398,8 @@ docstring Counters::counterLabel(docstring const & format)
 		       && lowercase(label[k]) <= 'z')
 			++k;
 		docstring counter = label.substr(j, k - j);
-		docstring repl = theCounter(counter);
+		docstring repl = callers? theCounter(counter, *callers): 
+			                      theCounter(counter);
 		label.replace(i, k - j + 4, repl);
 	}
 

src/Counters.h

@@ -18,6 +18,7 @@
 #include "support/docstring.h"
 
 #include <map>
+#include <set>
 
 
 namespace lyx {
@@ -105,7 +106,8 @@ public:
 	docstring theCounter(docstring const & c);
 	/// Replace om format all the LaTeX-like macros that depend on
 	/// counters.
-	docstring counterLabel(docstring const & format);
+	docstring counterLabel(docstring const & format, 
+	                       std::set<docstring> * callers = 0);
 	/// Are we in apendix?
 	bool appendix() const { return appendix_; };
 	/// Set the state variable indicating whether we are in appendix.
@@ -115,6 +117,10 @@ public:
 	/// Sets the current enclosing float.
 	void current_float(std::string const & f) { current_float_ = f; }
 private:
+	/// returns the expanded string representation of the counter
+	/// with recursion protection through callers.
+	docstring theCounter(docstring const & c, 
+	                     std::set<docstring> & callers);
 	/// Returns the value of the counter according to the
 	/// numbering scheme numbertype.
 	/* Available numbering schemes are arabic (1, 2,...), roman