Fix bug #8238: correct the forward argument of replace2string() in on_replacePB_clicked().

(cherry picked from commit 44b3278006)
Fix the wrong cursor move when forward flag is false:
The forward flag is used to place the cursor behind the replaced text if it's true.
But it's not correct to move the cursor if it's false. The cursor is in front of the
replacement already after the replaceSelectionWithString() was done.
(cherry picked from commit 430cf3ee5e)

src/frontends/qt4/GuiSpellchecker.cpp

@@ -315,8 +315,13 @@ void SpellcheckerWidget::on_replacePB_clicked()
 		return;
 	docstring const textfield = qstring_to_ucs4(d->ui.wordED->text());
 	docstring const replacement = qstring_to_ucs4(d->ui.replaceCO->currentText());
-	docstring const datastring = replace2string(replacement, textfield,
-		true, true, false, false);
+	docstring const datastring = 
+		replace2string(replacement, textfield,
+			true,   // case sensitive
+			true,   // match word
+			false,  // all words
+			true,   // forward
+			false); // find next
 
 	LYXERR(Debug::GUI, "Replace (" << replacement << ")");
 	dispatch(FuncRequest(LFUN_WORD_REPLACE, datastring));
@@ -332,8 +337,13 @@ void SpellcheckerWidget::on_replaceAllPB_clicked()
 		return;
 	docstring const textfield = qstring_to_ucs4(d->ui.wordED->text());
 	docstring const replacement = qstring_to_ucs4(d->ui.replaceCO->currentText());
-	docstring const datastring = replace2string(replacement, textfield,
-		true, true, true, true);
+	docstring const datastring =
+		replace2string(replacement, textfield,
+			true,   // case sensitive
+			true,   // match word
+			true,   // all words
+			true,   // forward
+			false); // find next
 
 	LYXERR(Debug::GUI, "Replace all (" << replacement << ")");
 	dispatch(FuncRequest(LFUN_WORD_REPLACE, datastring));

src/frontends/qt4/Menus.cpp

@@ -783,7 +783,11 @@ void MenuDefinition::expandSpellingSuggestions(BufferView const * bv)
 					MenuItem w(MenuItem::Command, toqstr(suggestion),
 						FuncRequest(LFUN_WORD_REPLACE, 
 							replace2string(suggestion, selection,
-								true, true, false, true, false)));
+								true,     // case sensitive
+								true,     // match word
+								false,    // all words
+								true,     // forward
+								false))); // find next
 					if (i < m)
 						add(w);
 					else

src/lyxfind.cpp

@@ -275,9 +275,6 @@ pair<bool, int> replaceOne(BufferView * bv, docstring searchstr,
 	if (forward) {
 		cur.pos() += replacestr.length();
 		LASSERT(cur.pos() <= cur.lastpos(), /* */);
-	} else {
-		cur.pos() -= replacestr.length();
-		LASSERT(cur.pos() >= 0, /* */);
 	}
 	if (findnext)
 		findOne(bv, searchstr, case_sens, whole, forward, false);

status.20x

@@ -138,6 +138,8 @@ What's new
 - When using a non-default language for the GUI, do not change locale
   settings of child proceses (bug 7741).
 
+- Fix crash in text replacement with spell checker (bug 8238).
+
 
 * DOCUMENTATION AND LOCALIZATION