Attachment "empty_buffer.patch" to
ticket [695422ffff]
added by
mdejong
2003-03-01 10:04:37.
2003-02-28 Mo DeJong <[email protected]>
* generic/tclIO.c (ReadBytes, ReadChars):
Handle the case of en empty input buffer explicitly.
This can happen when a cr appears at the end of an
input buffer that is in crlf or auto mode. A flag
is set to indicate that a lf at the start of the
next buffer means that a single lf should be added.
The problem in ReadBytes and ReadChars is that
they assume that the buffer will be non-empty.
It appears as though ReadBytes and ReadChars
still function properly in this case, so the
additional checks added here serve to make handling
of this case more clear.
Index: generic/tclIO.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclIO.c,v
retrieving revision 1.61
diff -u -r1.61 tclIO.c
--- generic/tclIO.c 19 Feb 2003 01:04:57 -0000 1.61
+++ generic/tclIO.c 1 Mar 2003 02:36:09 -0000
@@ -4531,6 +4538,7 @@
srcLen = bufPtr->nextAdded - bufPtr->nextRemoved;
toRead = bytesToRead;
+
if ((unsigned) toRead > (unsigned) srcLen) {
toRead = srcLen;
}
@@ -4564,6 +4572,15 @@
toRead--;
}
+ /*
+ * No need to go any farther when processing an empty buffer
+ * since a CR at the end of a previous buffer was handled above.
+ */
+
+ if (srcLen == 0) {
+ return -1;
+ }
+
srcRead = srcLen;
dstWrote = toRead;
if (TranslateInputEOL(statePtr, dst, src, &dstWrote, &srcRead) != 0) {
@@ -4689,10 +4706,12 @@
*/
statePtr->flags &= ~INPUT_NEED_NL;
- Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
- statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
- dst, TCL_UTF_MAX + 1, &srcRead, &dstWrote, &numChars);
- if ((dstWrote > 0) && (*dst == '\n')) {
+ if (srcLen > 0) {
+ Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
+ statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
+ dst, TCL_UTF_MAX + 1, &srcRead, &dstWrote, &numChars);
+ }
+ if ((srcLen > 0) && (dstWrote > 0) && (*dst == '\n')) {
/*
* The next char was a '\n'. Consume it and produce a '\n'.
*/
@@ -4710,6 +4729,15 @@
return 1;
}
+ /*
+ * No need to go any farther when processing an empty buffer
+ * since a CR at the end of a previous buffer was handled above.
+ */
+
+ if (srcLen == 0) {
+ return -1;
+ }
+
Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
statePtr->inputEncodingFlags, &statePtr->inputEncodingState, dst,
dstNeeded + TCL_UTF_MAX, &srcRead, &dstWrote, &numChars);
@@ -4724,23 +4752,15 @@
nextPtr = bufPtr->nextPtr;
if (nextPtr == NULL) {
- if (srcLen > 0) {
- /*
- * There isn't enough data in the buffers to complete the next
- * character, so we need to wait for more data before the next
- * file event can be delivered.
- *
- * SF #478856.
- *
- * The exception to this is if the input buffer was
- * completely empty before we tried to convert its
- * contents. Nothing in, nothing out, and no incomplete
- * character data. The conversion before the current one
- * was complete.
- */
+ /*
+ * There isn't enough data in the buffers to complete the next
+ * character, so we need to wait for more data before the next
+ * file event can be delivered.
+ *
+ * SF #478856.
+ */
- statePtr->flags |= CHANNEL_NEED_MORE_DATA;
- }
+ statePtr->flags |= CHANNEL_NEED_MORE_DATA;
return -1;
}
nextPtr->nextRemoved -= srcLen;
