Revise the Tcl_Append* machinery to tolerate NULL bytes to append.

Then have ReadChars() use that machinery to resize buffer receiving input,
rather than invent its own version.  Simplify ReadChars() callers.

1 files changed, 19 insertions, 10 deletions

diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c
index a929d04..d96d814 100644
--- a/generic/tclStringObj.c
+++ b/generic/tclStringObj.c
@@ -1139,7 +1139,8 @@ Tcl_AppendLimitedToObj(
 	if (ellipsis == NULL) {
 	    ellipsis = "...";
 	}
-	toCopy = Tcl_UtfPrev(bytes+limit+1-strlen(ellipsis), bytes) - bytes;
+	toCopy = (bytes == NULL) ? limit
+		: Tcl_UtfPrev(bytes+limit+1-strlen(ellipsis), bytes) - bytes;
     }
 
     /*
@@ -1386,7 +1387,8 @@ AppendUnicodeToUnicodeRep(
 	 * due to the reallocs below.
 	 */
 	int offset = -1;
-	if (unicode >= stringPtr->unicode && unicode <= stringPtr->unicode 
+	if (unicode && unicode >= stringPtr->unicode
+		&& unicode <= stringPtr->unicode
 		+ stringPtr->uallocated / sizeof(Tcl_UniChar)) {
 	    offset = unicode - stringPtr->unicode;
 	}
@@ -1405,8 +1407,10 @@ AppendUnicodeToUnicodeRep(
      * trailing null.
      */
 
-    memcpy(stringPtr->unicode + stringPtr->numChars, unicode,
-	    appendNumChars * sizeof(Tcl_UniChar));
+    if (unicode) {
+	memcpy(stringPtr->unicode + stringPtr->numChars, unicode,
+		appendNumChars * sizeof(Tcl_UniChar));
+    }
     stringPtr->unicode[numChars] = 0;
     stringPtr->numChars = numChars;
     stringPtr->allocated = 0;
@@ -1478,8 +1482,8 @@ AppendUtfToUnicodeRep(
     int numBytes)		/* Number of bytes of "bytes" to convert. */
 {
     Tcl_DString dsPtr;
-    int numChars;
-    Tcl_UniChar *unicode;
+    int numChars = numBytes;
+    Tcl_UniChar *unicode = NULL;
 
     if (numBytes < 0) {
 	numBytes = (bytes ? strlen(bytes) : 0);
@@ -1489,8 +1493,11 @@ AppendUtfToUnicodeRep(
     }
 
     Tcl_DStringInit(&dsPtr);
-    numChars = Tcl_NumUtfChars(bytes, numBytes);
-    unicode = (Tcl_UniChar *)Tcl_UtfToUniCharDString(bytes, numBytes, &dsPtr);
+    if (bytes) {
+	numChars = Tcl_NumUtfChars(bytes, numBytes);
+	unicode = (Tcl_UniChar *) Tcl_UtfToUniCharDString(bytes, numBytes,
+		&dsPtr);
+    }
     AppendUnicodeToUnicodeRep(objPtr, unicode, numChars);
     Tcl_DStringFree(&dsPtr);
 }
@@ -1547,7 +1554,7 @@ AppendUtfToUtfRep(
 	 * due to the reallocs below.
 	 */
 	int offset = -1;
-	if (bytes >= objPtr->bytes
+	if (bytes && bytes >= objPtr->bytes
 		&& bytes <= objPtr->bytes + objPtr->length) {
 	    offset = bytes - objPtr->bytes;
 	}
@@ -1585,7 +1592,9 @@ AppendUtfToUtfRep(
     stringPtr->numChars = -1;
     stringPtr->hasUnicode = 0;
 
-    memcpy(objPtr->bytes + oldLength, bytes, (size_t) numBytes);
+    if (bytes) {
+	memcpy(objPtr->bytes + oldLength, bytes, (size_t) numBytes);
+    }
     objPtr->bytes[newLength] = 0;
     objPtr->length = newLength;
 }