Fix a crash which occurs when RTL flag is turned on.

The crash was being caused by the fact that when moving back from the
beginning of the line to the previous line (by pressing RIGHT in an
RTL paragraph, or LEFT in an LTR one), Bidi metrics for the new line
do not yet exist, but an attempt is made to access them.

Basically, this patch was created by trying to "symmetrically" copy
cursorRight (which seems to work well) to cursorLeft (which was
problematic).

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@18389 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/Text2.cpp b/src/Text2.cpp
index e893889a299eefd7fd87a38daa3952d65746ada5..88339ffad2d6069543f39a053fd986bbff8dd47e 100644 (file)
--- a/src/Text2.cpp
+++ b/src/Text2.cpp
@@ -717,8 +717,12 @@ void Text::setCurrentFont(Cursor & cur)
        pos_type pos = cur.pos();
        Paragraph & par = cur.paragraph();
 
-       if (cur.boundary() && pos > 0)
+       if (cur.boundary() && pos > 0 && pos < cur.lastpos()) {
                --pos;
+               // We may have just moved to the previous row --- 
+               // we're going to be needing its bidi tables!
+               bidi.computeTables(par, cur.buffer(), cur.textRow());
+       }
 
        if (pos > 0) {
                if (pos == cur.lastpos())
@@ -904,9 +908,18 @@ bool Text::checkAndActivateInset(Cursor & cur, bool front)
                return false;
        if (cur.pos() == cur.lastpos())
                return false;
-       Inset * inset = cur.nextInset();
+       Inset * inset = front ? cur.nextInset() : cur.prevInset();
        if (!isHighlyEditableInset(inset))
                return false;
+       /*
+        * Apparently, when entering an inset we are expected to be positioned
+        * *before* it in the containing paragraph, regardless of the direction
+        * from which we are entering. Otherwise, cursor placement goes awry,
+        * and when we exit from the beginning, we'll be placed *after* the
+        * inset.
+        */ 
+       if (!front)
+               --cur.pos();
        inset->edit(cur, front);
        return true;
 }
@@ -917,27 +930,35 @@ bool Text::cursorLeft(Cursor & cur)
        // Tell BufferView to test for FitCursor in any case!
        cur.updateFlags(Update::FitCursor);
 
-       if (!cur.boundary() && cur.pos() > 0 &&
-           cur.textRow().pos() == cur.pos() &&
-           !cur.paragraph().isLineSeparator(cur.pos()-1) &&
-           !cur.paragraph().isNewline(cur.pos()-1)) {
-               return setCursor(cur, cur.pit(), cur.pos(), true, true);
-       }
-       if (cur.pos() != 0) {
-               bool updateNeeded = setCursor(cur, cur.pit(), cur.pos() - 1, true, false);
+       if (cur.pos() > 0) {
+               if (cur.boundary())
+                       return setCursor(cur, cur.pit(), cur.pos(), true, false);
+
+               bool updateNeeded = false;
+               // If checkAndActivateInset returns true, that means that
+               // the cursor was placed inside it, so we're done
                if (!checkAndActivateInset(cur, false)) {
-                       /** FIXME: What's this cause purpose???
-                       bool boundary = cur.boundary();
-                       if (false && !boundary &&
-                           bidi.isBoundary(cur.buffer(), cur.paragraph(), cur.pos() + 1))
-                               updateNeeded |=
-                                       setCursor(cur, cur.pit(), cur.pos() + 1, true, true);
-                       */
+                       if (!cur.boundary() && 
+                           cur.textRow().pos() == cur.pos() 
+                           // FIXME: the following two conditions are copied
+                           // from cursorRight; however, isLineSeparator()
+                           // is definitely wrong here, isNewline I'm not sure
+                           // about. I'm leaving them as comments for now,
+                           // until we understand why they should or shouldn't
+                           // be here.
+                           /*&& 
+                           !cur.paragraph().isLineSeparator(cur.pos()-1) &&
+                           !cur.paragraph().isNewline(cur.pos() - 1)*/) {
+                               updateNeeded |= setCursor(cur, cur.pit(), cur.pos(), 
+                                                                                 true, true);
+                       }
+                       updateNeeded |= setCursor(cur, cur.pit(),cur.pos() - 1, 
+                                                                         true, false);
                }
                return updateNeeded;
        }
 
-       if (cur.pit() != 0) {
+       if (cur.pit() > 0) {
                // Steps into the paragraph above
                return setCursor(cur, cur.pit() - 1, getPar(cur.pit() - 1).size());
        }
@@ -956,6 +977,8 @@ bool Text::cursorRight(Cursor & cur)
                                         true, false);
 
                bool updateNeeded = false;
+               // If checkAndActivateInset returns true, that means that 
+               // the cursor was placed inside it, so we're done
                if (!checkAndActivateInset(cur, true)) {
                        if (cur.textRow().endpos() == cur.pos() + 1 &&
                            cur.textRow().endpos() != cur.lastpos() &&
@@ -964,9 +987,6 @@ bool Text::cursorRight(Cursor & cur)
                                cur.boundary(true);
                        }
                        updateNeeded |= setCursor(cur, cur.pit(), cur.pos() + 1, true, cur.boundary());
-                       if (false && bidi.isBoundary(cur.buffer(), cur.paragraph(),
-                                                    cur.pos()))
-                               updateNeeded |= setCursor(cur, cur.pit(), cur.pos(), true, true);
                }
                return updateNeeded;
        }