(svn r14514) -Codechange: use 'size' instead of 'length' for querystring and textbuf, explicitly say it includes the terminating zero

-Fix: one couldn't rename things with too long default/automatic name
-Fix: buffer overflow in console when too long (1024 bytes) command was entered

1 files changed, 36 insertions, 32 deletions

diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index e9d374990..76061461f 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -793,8 +793,8 @@ static void DelChar(Textbuf *tb, bool backspace)
 	}
 
 	/* Move the remaining characters over the marker */
-	memmove(s, s + len, tb->length - (s - tb->buf) - len + 1);
-	tb->length -= len;
+	memmove(s, s + len, tb->size - (s - tb->buf) - len);
+	tb->size -= len;
 }
 
 /**
@@ -809,7 +809,7 @@ bool DeleteTextBufferChar(Textbuf *tb, int delmode)
 	if (delmode == WKC_BACKSPACE && tb->caretpos != 0) {
 		DelChar(tb, true);
 		return true;
-	} else if (delmode == WKC_DELETE && tb->caretpos < tb->length) {
+	} else if (delmode == WKC_DELETE && tb->caretpos < tb->size - 1) {
 		DelChar(tb, false);
 		return true;
 	}
@@ -823,9 +823,9 @@ bool DeleteTextBufferChar(Textbuf *tb, int delmode)
  */
 void DeleteTextBufferAll(Textbuf *tb)
 {
-	memset(tb->buf, 0, tb->maxlength);
-	tb->length = tb->width = 0;
-	tb->caretpos = tb->caretxoffs = 0;
+	memset(tb->buf, 0, tb->maxsize);
+	tb->size = 1;
+	tb->width = tb->caretpos = tb->caretxoffs = 0;
 }
 
 /**
@@ -840,11 +840,11 @@ bool InsertTextBufferChar(Textbuf *tb, WChar key)
 {
 	const byte charwidth = GetCharacterWidth(FS_NORMAL, key);
 	uint16 len = (uint16)Utf8CharLen(key);
-	if (tb->length < (tb->maxlength - len) && (tb->maxwidth == 0 || tb->width + charwidth <= tb->maxwidth)) {
-		memmove(tb->buf + tb->caretpos + len, tb->buf + tb->caretpos, tb->length - tb->caretpos + 1);
+	if (tb->size + len <= tb->maxsize && (tb->maxwidth == 0 || tb->width + charwidth <= tb->maxwidth)) {
+		memmove(tb->buf + tb->caretpos + len, tb->buf + tb->caretpos, tb->size - tb->caretpos);
 		Utf8Encode(tb->buf + tb->caretpos, key);
-		tb->length += len;
-		tb->width  += charwidth;
+		tb->size  += len;
+		tb->width += charwidth;
 
 		tb->caretpos   += len;
 		tb->caretxoffs += charwidth;
@@ -876,7 +876,7 @@ bool MoveTextBufferPos(Textbuf *tb, int navmode)
 			break;
 
 		case WKC_RIGHT:
-			if (tb->caretpos < tb->length) {
+			if (tb->caretpos < tb->size - 1) {
 				WChar c;
 
 				tb->caretpos   += (uint16)Utf8Decode(&c, tb->buf + tb->caretpos);
@@ -892,7 +892,7 @@ bool MoveTextBufferPos(Textbuf *tb, int navmode)
 			return true;
 
 		case WKC_END:
-			tb->caretpos = tb->length;
+			tb->caretpos = tb->size - 1;
 			tb->caretxoffs = tb->width;
 			return true;
 
@@ -908,16 +908,18 @@ bool MoveTextBufferPos(Textbuf *tb, int navmode)
  * and the maximum length of this buffer
  * @param tb Textbuf type which is getting initialized
  * @param buf the buffer that will be holding the data for input
- * @param maxlength maximum length in characters of this buffer
+ * @param maxsize maximum size in bytes, including terminating '\0'
  * @param maxwidth maximum length in pixels of this buffer. If reached, buffer
- * cannot grow, even if maxlength would allow because there is space. A length
- * of zero '0' means the buffer is only restricted by maxlength */
-void InitializeTextBuffer(Textbuf *tb, const char *buf, uint16 maxlength, uint16 maxwidth)
+ * cannot grow, even if maxsize would allow because there is space. Width
+ * of zero '0' means the buffer is only restricted by maxsize */
+void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 maxsize, uint16 maxwidth)
 {
-	tb->buf = (char*)buf;
-	tb->maxlength = maxlength;
-	tb->maxwidth  = maxwidth;
-	tb->caret = true;
+	assert(maxsize != 0);
+
+	tb->buf      = buf;
+	tb->maxsize  = maxsize;
+	tb->maxwidth = maxwidth;
+	tb->caret    = true;
 	UpdateTextBufferSize(tb);
 }
 
@@ -930,17 +932,19 @@ void InitializeTextBuffer(Textbuf *tb, const char *buf, uint16 maxlength, uint16
 void UpdateTextBufferSize(Textbuf *tb)
 {
 	const char *buf = tb->buf;
-	WChar c = Utf8Consume(&buf);
 
 	tb->width = 0;
-	tb->length = 0;
+	tb->size = 1; // terminating zero
 
-	for (; c != '\0' && tb->length < (tb->maxlength - 1); c = Utf8Consume(&buf)) {
+	WChar c;
+	while ((c = Utf8Consume(&buf)) != '\0') {
 		tb->width += GetCharacterWidth(FS_NORMAL, c);
-		tb->length += Utf8CharLen(c);
+		tb->size += Utf8CharLen(c);
 	}
 
-	tb->caretpos = tb->length;
+	assert(tb->size <= tb->maxsize);
+
+	tb->caretpos = tb->size - 1;
 	tb->caretxoffs = tb->width;
 }
 
@@ -1163,22 +1167,22 @@ static const WindowDesc _query_string_desc = {
 /** Show a query popup window with a textbox in it.
  * @param str StringID for the text shown in the textbox
  * @param caption StringID of text shown in caption of querywindow
- * @param maxlen maximum length in characters allowed
+ * @param maxsize maximum size in bytes (including terminating '\0')
  * @param maxwidth maximum width in pixels allowed
  * @param parent pointer to a Window that will handle the events (ok/cancel) of this
  *        window. If NULL, results are handled by global function HandleOnEditText
  * @param afilter filters out unwanted character input
  * @param flags various flags, @see QueryStringFlags
  */
-void ShowQueryString(StringID str, StringID caption, uint maxlen, uint maxwidth, Window *parent, CharSetFilter afilter, QueryStringFlags flags)
+void ShowQueryString(StringID str, StringID caption, uint maxsize, uint maxwidth, Window *parent, CharSetFilter afilter, QueryStringFlags flags)
 {
 	DeleteWindowById(WC_QUERY_STRING, 0);
 	DeleteWindowById(WC_SAVELOAD, 0);
 
-	QueryStringWindow *w = new QueryStringWindow(maxlen + 1, &_query_string_desc, parent);
+	QueryStringWindow *w = new QueryStringWindow(maxsize, &_query_string_desc, parent);
 
-	GetString(w->edit_str_buf, str, &w->edit_str_buf[maxlen]);
-	w->edit_str_buf[maxlen] = '\0';
+	GetString(w->edit_str_buf, str, &w->edit_str_buf[maxsize - 1]);
+	w->edit_str_buf[maxsize - 1] = '\0';
 
 	if ((flags & QSF_ACCEPT_UNCHANGED) == 0) w->orig = strdup(w->edit_str_buf);
 
@@ -1194,7 +1198,7 @@ void ShowQueryString(StringID str, StringID caption, uint maxlen, uint maxwidth,
 	w->LowerWidget(QUERY_STR_WIDGET_TEXT);
 	w->caption = caption;
 	w->afilter = afilter;
-	InitializeTextBuffer(&w->text, w->edit_str_buf, maxlen, maxwidth);
+	InitializeTextBuffer(&w->text, w->edit_str_buf, maxsize, maxwidth);
 }
 
 
@@ -1583,7 +1587,7 @@ struct SaveLoadWindow : public QueryStringBaseWindow {
 						ShowHeightmapLoad();
 					} else {
 						/* SLD_SAVE_GAME, SLD_SAVE_SCENARIO copy clicked name to editbox */
-						ttd_strlcpy(this->text.buf, file->title, this->text.maxlength);
+						ttd_strlcpy(this->text.buf, file->title, this->text.maxsize);
 						UpdateTextBufferSize(&this->text);
 						this->InvalidateWidget(10);
 					}