Restore currently entered text in chat entry textbox after going through history with Ctrl-PgUp/PgDown (#2680)

Author: Ansariel

indra/llui/llchatentry.cpp

@@ -45,7 +45,8 @@ LLChatEntry::LLChatEntry(const Params& p)
     mExpandLinesCount(p.expand_lines_count),
     mPrevLinesCount(0),
     mSingleLineMode(false),
-    mPrevExpandedLineCount(S32_MAX)
+    mPrevExpandedLineCount(S32_MAX),
+    mCurrentInput("")
 {
     // Initialize current history line iterator
     mCurrentHistoryLine = mLineHistory.begin();
@@ -189,13 +190,19 @@ bool LLChatEntry::handleSpecialKey(const KEY key, const MASK mask)
         {
             needsReflow();
         }
+        mCurrentInput = "";
         break;
 
     case KEY_UP:
         if (mHasHistory && MASK_CONTROL == mask)
         {
             if (!mLineHistory.empty() && mCurrentHistoryLine > mLineHistory.begin())
             {
+                if (mCurrentHistoryLine == mLineHistory.end())
+                {
+                    mCurrentInput = getText();
+                }
+
                 setText(*(--mCurrentHistoryLine));
                 endOfDoc();
             }
@@ -210,16 +217,15 @@ bool LLChatEntry::handleSpecialKey(const KEY key, const MASK mask)
     case KEY_DOWN:
         if (mHasHistory && MASK_CONTROL == mask)
         {
-            if (!mLineHistory.empty() && mCurrentHistoryLine < (mLineHistory.end() - 1) )
+            if (!mLineHistory.empty() && mCurrentHistoryLine < (mLineHistory.end() - 1))
             {
                 setText(*(++mCurrentHistoryLine));
                 endOfDoc();
             }
-            else if (!mLineHistory.empty() && mCurrentHistoryLine == (mLineHistory.end() - 1) )
+            else if (!mLineHistory.empty() && mCurrentHistoryLine == (mLineHistory.end() - 1))
             {
                 mCurrentHistoryLine++;
-                std::string empty("");
-                setText(empty);
+                setText(mCurrentInput);
                 needsReflow();
                 endOfDoc();
             }

indra/llui/llchatentry.h

@@ -101,6 +101,8 @@ class LLChatEntry : public LLTextEditor
     S32                                 mExpandLinesCount;
     S32                                 mPrevLinesCount;
     S32                                 mPrevExpandedLineCount;
+
+    std::string                         mCurrentInput;
 };
 
 #endif /* LLCHATENTRY_H_ */