7 files changed, 36 insertions, 11 deletions

diff --git a/include/Scintilla.h b/include/Scintilla.h
index 246301578..543edeaf1 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -225,6 +225,8 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SCI_USERLISTSHOW 2117
 #define SCI_AUTOCSETAUTOHIDE 2118
 #define SCI_AUTOCGETAUTOHIDE 2119
+#define SCI_AUTOCSETDROPRESTOFWORD 2270
+#define SCI_AUTOCGETDROPRESTOFWORD 2271
 #define SCI_SETINDENT 2122
 #define SCI_GETINDENT 2123
 #define SCI_SETUSETABS 2124
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index 2f9de7d5a..a74f69075 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -540,6 +540,12 @@ set void AutoCSetAutoHide=2118(bool autoHide,)
 # Retrieve whether or not autocompletion is hidden automatically when nothing matches
 get bool AutoCGetAutoHide=2119(,)
 
+# Set whether or not autocompletion deletes any word characters after the inserted text upon completion
+set void AutoCSetDropRestOfWord=2270(bool dropRestOfWord,)
+
+# Retrieve whether or not autocompletion deletes any word characters after the inserted text upon completion
+get bool AutoCGetDropRestOfWord=2271(,)
+
 # Set the number of spaces used for one level of indentation.
 set void SetIndent=2122(int indentSize,)
 
diff --git a/src/AutoComplete.cxx b/src/AutoComplete.cxx
index 7f7412e43..f67d42b0b 100644
--- a/src/AutoComplete.cxx
+++ b/src/AutoComplete.cxx
@@ -22,7 +22,8 @@ AutoComplete::AutoComplete() :
 	posStart(0),
 	startLen(0),
 	cancelAtStartPos(true),
-	autoHide(true) {
+	autoHide(true),
+	dropRestOfWord(false)	{
 	stopChars[0] = '\0';
 	fillUpChars[0] = '\0';
 }
diff --git a/src/AutoComplete.h b/src/AutoComplete.h
index 79d467529..80dc95dc0 100644
--- a/src/AutoComplete.h
+++ b/src/AutoComplete.h
@@ -25,6 +25,7 @@ public:
 	/// Should autocompletion be canceled if editor's currentPos <= startPos?
 	bool cancelAtStartPos;
 	bool autoHide;
+	bool dropRestOfWord;
 
 	AutoComplete();
 	~AutoComplete();
diff --git a/src/Document.cxx b/src/Document.cxx
index 8483d86f1..b7acc8610 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -722,13 +722,16 @@ Document::charClassification Document::WordCharClass(unsigned char ch) {
  * Used by commmands that want to select whole words.
  * Finds the start of word at pos when delta < 0 or the end of the word when delta >= 0.
  */
-int Document::ExtendWordSelect(int pos, int delta) {
+int Document::ExtendWordSelect(int pos, int delta, bool onlyWordCharacters) {
+	charClassification ccStart = ccWord;
 	if (delta < 0) {
-		charClassification ccStart = WordCharClass(cb.CharAt(pos-1));
+		if (!onlyWordCharacters)
+			ccStart = WordCharClass(cb.CharAt(pos-1));
 		while (pos > 0 && (WordCharClass(cb.CharAt(pos - 1)) == ccStart))
 			pos--;
 	} else {
-		charClassification ccStart = WordCharClass(cb.CharAt(pos));
+		if (!onlyWordCharacters)
+			ccStart = WordCharClass(cb.CharAt(pos));
 		while (pos < (Length()) && (WordCharClass(cb.CharAt(pos)) == ccStart))
 			pos++;
 	}
diff --git a/src/Document.h b/src/Document.h
index 09814fec8..51cfa9d53 100644
--- a/src/Document.h
+++ b/src/Document.h
@@ -177,7 +177,7 @@ public:
 	int GetFoldParent(int line);
 
 	void Indent(bool forwards);
-	int ExtendWordSelect(int pos, int delta);
+	int ExtendWordSelect(int pos, int delta, bool onlyWordCharacters=false);
 	int NextWordStart(int pos, int delta);
 	int Length() { return cb.Length(); }
 	long FindText(int minPos, int maxPos, const char *s, 
diff --git a/src/ScintillaBase.cxx b/src/ScintillaBase.cxx
index 2994f42db..4a9b87670 100644
--- a/src/ScintillaBase.cxx
+++ b/src/ScintillaBase.cxx
@@ -307,14 +307,18 @@ void ScintillaBase::AutoCompleteCompleted(char fillUp/*='\0'*/) {
 		scn.lParam = 0;
 		scn.text = userListSelected.c_str();
 		NotifyParent(scn);
-		return ;
+		return;
 	}
 
 	Position firstPos = ac.posStart - ac.startLen;
-	if (currentPos < firstPos)
-		return ;
-	if (currentPos != firstPos) {
-		pdoc->DeleteChars(firstPos, currentPos - firstPos);
+	Position endPos = currentPos;
+	if (ac.dropRestOfWord)
+		endPos = pdoc->ExtendWordSelect(endPos, 1, true);
+	if (endPos < firstPos)
+		return;
+	pdoc->BeginUndoAction();
+	if (endPos != firstPos) {
+		pdoc->DeleteChars(firstPos, endPos - firstPos);
 	}
 	SetEmptySelection(ac.posStart);
 	if (item != -1) {
@@ -324,6 +328,7 @@ void ScintillaBase::AutoCompleteCompleted(char fillUp/*='\0'*/) {
 		pdoc->InsertString(firstPos, piece.c_str());
 		SetEmptySelection(firstPos + piece.length());
 	}
+	pdoc->EndUndoAction();
 }
 
 void ScintillaBase::ContextMenu(Point pt) {
@@ -404,7 +409,7 @@ void ScintillaBase::NotifyStyleToNeeded(int endStyleNeeded) {
 		int lineEndStyled = WndProc(SCI_LINEFROMPOSITION, endStyled, 0);
 		endStyled = WndProc(SCI_POSITIONFROMLINE, lineEndStyled, 0);
 		Colourise(endStyled, endStyleNeeded);
-		return ;
+		return;
 	}
 #endif
 	Editor::NotifyStyleToNeeded(endStyleNeeded);
@@ -483,6 +488,13 @@ sptr_t ScintillaBase::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lPara
 	case SCI_AUTOCGETAUTOHIDE:
 		return ac.autoHide;
 
+	case SCI_AUTOCSETDROPRESTOFWORD:
+		ac.dropRestOfWord = wParam != 0;
+		break;
+
+	case SCI_AUTOCGETDROPRESTOFWORD:
+		return ac.dropRestOfWord;
+
 	case SCI_CALLTIPSHOW: {
 			AutoCompleteCancel();
 			if (!ct.wCallTip.Created()) {