Fix ruby alignment, fix one possible crash, ignore empty non-linear flows

cr3gui/data/html5.css

@@ -243,6 +243,7 @@ sup {
 ruby {
   display: ruby;
   text-align: center;
+  text-align-last: initial;
   text-indent: 0;
 }
 rb, rubyBox[T=rb] {

crengine/include/lvdocview.h

@@ -367,6 +367,8 @@ class LVDocView : public CacheLoadingCallback
     ldomXPointer m_cursorPos;
 
     lString32 m_pageHeaderOverride;
+    /// custom page info (curpage / nbpages %) can be set by frontend
+    lString32 m_pageInfoOverride;
 
     int m_drawBufferBits;
 
@@ -422,6 +424,8 @@ class LVDocView : public CacheLoadingCallback
     void setDrawBufferBits( int bits ) { m_drawBufferBits = bits; }
     /// substitute page header with custom text (e.g. to be used while loading)
     void setPageHeaderOverride( lString32 s );
+    /// substitute page info (curpage / nbpages %) with custom text
+    void setPageInfoOverride( lString32 s );
     /// get screen rectangle for current cursor position, returns false if not visible
     bool getCursorRect( lvRect & rc, bool scrollToCursor = false )
     {

crengine/include/lvpagesplitter.h

@@ -236,7 +236,7 @@ class LVRendPageList : public LVPtrVector<LVRendPageInfo>
 public:
     LVRendPageList() : has_nonlinear_flows(false) {}
     int FindNearestPage( int y, int direction );
-    void setHasNonLinearFlows() { has_nonlinear_flows=true; }
+    void setHasNonLinearFlows( bool hasnonlinearflows ) { has_nonlinear_flows = hasnonlinearflows; }
     bool hasNonLinearFlows() { return has_nonlinear_flows; }
     bool serialize( SerialBuf & buf );
     bool deserialize( SerialBuf & buf );
@@ -412,6 +412,8 @@ class LVRendPageContext
     int current_flow;
     // maximum flow encountered so far
     int max_flow;
+    // to know if current flow got some lines
+    bool current_flow_empty;
 
     LVHashTable<lString32, LVFootNoteRef> footNotes;
 

crengine/src/lvdocview.cpp

@@ -1721,6 +1721,12 @@ void LVDocView::setPageHeaderOverride(lString32 s) {
 	clearImageCache();
 }
 
+/// substitute page info (curpage / nbpages %) with custom text
+void LVDocView::setPageInfoOverride(lString32 s) {
+	m_pageInfoOverride = s;
+	clearImageCache();
+}
+
 /// draw page header to buffer
 void LVDocView::drawPageHeader(LVDrawBuf * drawbuf, const lvRect & headerRc,
 		int pageIndex, int phi, int pageCount) {
@@ -1872,7 +1878,10 @@ void LVDocView::drawPageHeader(LVDrawBuf * drawbuf, const lvRect & headerRc,
 			}
 		}
 		lString32 pageinfo;
-		if (pageCount > 0) {
+		if (!m_pageInfoOverride.empty()) {
+			pageinfo = m_pageInfoOverride;
+		}
+		else if (pageCount > 0) {
 			if (phi & PGHDR_PAGE_NUMBER)
                 pageinfo += fmt::decimal( getExternalPageNumber(pageIndex) + 1 );
             if (phi & PGHDR_PAGE_COUNT) {

crengine/src/lvpagesplitter.cpp

@@ -51,7 +51,7 @@ static LVRendPageContext * main_context = NULL;
 LVRendPageContext::LVRendPageContext(LVRendPageList * pageList, int pageHeight, int docFontSize, bool gatherLines)
     : callback(NULL), totalFinalBlocks(0)
     , renderedFinalBlocks(0), lastPercent(-1), page_list(pageList), page_h(pageHeight)
-    , doc_font_size(docFontSize), gather_lines(gatherLines), current_flow(0), max_flow(0)
+    , doc_font_size(docFontSize), gather_lines(gatherLines), current_flow(0), max_flow(0), current_flow_empty(false)
     , footNotes(64), curr_note(NULL)
 {
     if ( callback ) {
@@ -157,13 +157,21 @@ void LVRendPageContext::newFlow( bool nonlinear )
 {
     /// A new non-linear flow gets the next number
     /// A new linear flow simply gets appended to flow 0
+    if ( current_flow > 0 && current_flow_empty ) {
+        // We created a flow but didn't fill it: have it like it never happened
+        max_flow--;
+        if ( page_list )
+            page_list->setHasNonLinearFlows(max_flow > 0);
+        current_flow_empty = false;
+    }
     if (nonlinear) {
-       max_flow++;
-       current_flow = max_flow;
-       if ( page_list )
-           page_list->setHasNonLinearFlows();
+        max_flow++;
+        current_flow = max_flow;
+        current_flow_empty = true;
+        if ( page_list )
+            page_list->setHasNonLinearFlows(max_flow > 0);
     } else {
-       current_flow = 0;
+        current_flow = 0;
     }
 }
 
@@ -177,6 +185,7 @@ void LVRendPageContext::AddLine( int starty, int endy, int flags )
         flags |= RN_SPLIT_FOOT_NOTE;
     LVRendLineInfo * line = new LVRendLineInfo(starty, endy, flags, current_flow);
     lines.add( line );
+    current_flow_empty = false;
     if ( curr_note != NULL ) {
         //CRLog::trace("adding line to note (%d)", line->start);
         curr_note->addLine( line );

crengine/src/lvrend.cpp

@@ -11565,10 +11565,12 @@ void getRenderedWidths(ldomNode * node, int &maxWidth, int &minWidth, int direct
                 lastSpaceWidth = 0;
                 int _maxw = 0;
                 int _minw = 0;
-                if ( is_img && img_width > 0) {
-                    // Inline img with a fixed width
-                    _maxw = img_width;
-                    _minw = img_width;
+                if ( is_img ) {
+                    if ( img_width > 0) {
+                        // Inline img with a fixed width
+                        _maxw = img_width;
+                        _minw = img_width;
+                    }
                 }
                 else {
                     // Get the rendered width of the inlineBox