From dbf2d632693be0d2625235d10ccd531694c03fcd Mon Sep 17 00:00:00 2001
From: henrikjust <henrikjust@f0f2a975-2e09-46c8-9428-3b39399b9f3c>
Date: Thu, 23 Feb 2012 10:18:38 +0000
Subject: [PATCH] w2l: Detect and ignore empty formulas

git-svn-id: svn://svn.code.sf.net/p/writer2latex/code/trunk@131 f0f2a975-2e09-46c8-9428-3b39399b9f3c
---
 source/distro/changelog.txt                   |  4 +-
 .../writer2latex/latex/DrawConverter.java     | 15 +++---
 .../writer2latex/latex/MathmlConverter.java   | 47 +++++++++++--------
 3 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/source/distro/changelog.txt b/source/distro/changelog.txt
index cdd5387..2851863 100644
--- a/source/distro/changelog.txt
+++ b/source/distro/changelog.txt
@@ -2,7 +2,9 @@ Changelog for Writer2LaTeX version 1.0 -> 1.2
 
 ---------- version 1.1.9 ----------
 
-[w2l] The StarMath now avoids more redundant braces
+[w2l] Properly detect and ignore empty formulas (avoiding any occurrences of $ $ in the document)
+
+[w2l] The StarMath converter now avoids redundant braces
 
 [w2l] The StarMath converter is now a little more tolerant on errors like missing operands for a binary operator
   (import from MS Word may create such errors)
diff --git a/source/java/writer2latex/latex/DrawConverter.java b/source/java/writer2latex/latex/DrawConverter.java
index 3e494df..97adddd 100644
--- a/source/java/writer2latex/latex/DrawConverter.java
+++ b/source/java/writer2latex/latex/DrawConverter.java
@@ -16,11 +16,11 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  *  MA  02111-1307  USA
  *
- *  Copyright: 2002-2010 by Henrik Just
+ *  Copyright: 2002-2012 by Henrik Just
  *
  *  All Rights Reserved.
  * 
- *  Version 1.2 (2010-10-09)
+ *  Version 1.2 (2012-02-23)
  *
  */
  
@@ -157,10 +157,13 @@ public class DrawConverter extends ConverterHelper {
                             if (formula==null) {
                             	formula = Misc.getChildByTagName(formuladoc,XMLString.MATH_MATH);
                             }
-                            ldp.append(" $")
-                               .append(palette.getMathmlCv().convert(settings,formula))
-                               .append("$");
-                            if (Character.isLetterOrDigit(OfficeReader.getNextChar(node))) { ldp.append(" "); }
+                            String sLaTeX = palette.getMathmlCv().convert(settings,formula);
+                            if (!" ".equals(sLaTeX)) { // ignore empty formulas
+                            	ldp.append(" $")
+                            	   .append(sLaTeX)
+                            	   .append("$");
+                                if (Character.isLetterOrDigit(OfficeReader.getNextChar(node))) { ldp.append(" "); }
+                            }
                         }
                         catch (org.xml.sax.SAXException e) {
                             e.printStackTrace();
diff --git a/source/java/writer2latex/latex/MathmlConverter.java b/source/java/writer2latex/latex/MathmlConverter.java
index 123d599..674da80 100644
--- a/source/java/writer2latex/latex/MathmlConverter.java
+++ b/source/java/writer2latex/latex/MathmlConverter.java
@@ -16,11 +16,11 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  *  MA  02111-1307  USA
  *
- *  Copyright: 2002-2010 by Henrik Just
+ *  Copyright: 2002-2012 by Henrik Just
  *
  *  All Rights Reserved.
  * 
- *  Version 1.2 (2010-04-29)
+ *  Version 1.2 (2012-02-23)
  *
  */
 
@@ -103,7 +103,13 @@ public final class MathmlConverter extends ConverterHelper {
         // TODO: Investigate if Vasil I. Yaroshevich's MathML->LaTeX
         // XSL transformation could be used here. (Potential problem:
         // OOo uses MathML 1.01, not MathML 2)
-        return "\\text{Warning: No StarMath annotation}";
+		if (formula.hasChildNodes()) {
+			return "\\text{Warning: No StarMath annotation}";
+		}
+		else { // empty formula
+			return " ";
+		}
+			
     }
 	
     // Data for display equations
@@ -163,22 +169,25 @@ public final class MathmlConverter extends ConverterHelper {
     }
     
     private void handleDisplayEquation(Element equation, Element sequence, LaTeXDocumentPortion ldp) {
-        if (sequence!=null) {
-            // Numbered equation
-            ldp.append("\\begin{equation}");
-            palette.getFieldCv().handleSequenceLabel(sequence,ldp);
-            ldp.nl()
-               .append(convert(null,equation)).nl()
-               .append("\\end{equation}").nl();
-            if (bAddParAfterDisplay) { ldp.nl(); }
-        }
-        else {
-            // Unnumbered equation
-            ldp.append("\\begin{equation*}").nl()
-               .append(convert(null,equation)).nl()
-               .append("\\end{equation*}").nl();
-            if (bAddParAfterDisplay) { ldp.nl(); }
-        }    	
+    	String sLaTeX = convert(null,equation);
+    	if (!" ".equals(sLaTeX)) { // ignore empty formulas
+    		if (sequence!=null) {
+    			// Numbered equation
+    			ldp.append("\\begin{equation}");
+    			palette.getFieldCv().handleSequenceLabel(sequence,ldp);
+    			ldp.nl()
+    			.append(sLaTeX).nl()
+    			.append("\\end{equation}").nl();
+    			if (bAddParAfterDisplay) { ldp.nl(); }
+    		}
+    		else {
+    			// Unnumbered equation
+    			ldp.append("\\begin{equation*}").nl()
+    			.append(sLaTeX).nl()
+    			.append("\\end{equation*}").nl();
+    			if (bAddParAfterDisplay) { ldp.nl(); }
+    		}    	
+    	}
     }
 	
     private boolean parseDisplayEquation(Node node) {