Get rid of hackery function TkUtfPrev(): No longer necessary due to TIP #575

3 files changed, 11 insertions, 54 deletions

diff --git a/generic/tkInt.h b/generic/tkInt.h
index ee453ea..5ef38ab 100644
--- a/generic/tkInt.h
+++ b/generic/tkInt.h
@@ -1417,14 +1417,13 @@ MODULE_SCOPE void	TkUnixSetXftClipRegion(Region clipRegion);
 # define c_class class
 #endif
 
-#if TCL_UTF_MAX > 4
+/* Tcl 8.6 has a different definition of Tcl_UniChar than other Tcl versions for TCL_UTF_MAX > 3 */
+#if TCL_UTF_MAX > (3 + (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 6))
 #   define TkUtfToUniChar(src, ch) (size_t)(((int (*)(const char *, int *))Tcl_UtfToUniChar)(src, ch))
 #   define TkUniCharToUtf(ch, src) (size_t)(((int (*)(int, char *))Tcl_UniCharToUtf)(ch, src))
-#   define TkUtfPrev Tcl_UtfPrev
 #else
     MODULE_SCOPE size_t TkUtfToUniChar(const char *, int *);
     MODULE_SCOPE size_t TkUniCharToUtf(int, char *);
-    MODULE_SCOPE const char *TkUtfPrev(const char *, const char *);
 #endif
 
 #if defined(_WIN32) && !defined(STATIC_BUILD) && TCL_MAJOR_VERSION < 9
diff --git a/generic/tkTextIndex.c b/generic/tkTextIndex.c
index eea8f50..7d55331 100644
--- a/generic/tkTextIndex.c
+++ b/generic/tkTextIndex.c
@@ -436,7 +436,7 @@ TkTextMakeByteIndex(
 		 */
 
 		start = segPtr->body.chars + (byteIndex - index);
-		p = TkUtfPrev(start, segPtr->body.chars);
+		p = Tcl_UtfPrev(start, segPtr->body.chars);
 		p += TkUtfToUniChar(p, &ch);
 		indexPtr->byteIndex += p - start;
 	    }
@@ -2126,7 +2126,7 @@ TkTextIndexBackChars(
 	    if (segPtr->typePtr == &tkTextCharType) {
 		start = segPtr->body.chars;
 		end = segPtr->body.chars + segSize;
-		for (p = end; ; p = TkUtfPrev(p, start)) {
+		for (p = end; ; p = Tcl_UtfPrev(p, start)) {
 		    if (charCount == 0) {
 			dstPtr->byteIndex -= (end - p);
 			goto backwardCharDone;
@@ -2367,7 +2367,7 @@ StartEnd(
 		}
 		if (offset + 1 > 1) {
 		    chSize = (segPtr->body.chars + offset
-			    - TkUtfPrev(segPtr->body.chars + offset,
+			    - Tcl_UtfPrev(segPtr->body.chars + offset,
 			    segPtr->body.chars));
 		}
 		firstChar = 0;
diff --git a/generic/tkUtil.c b/generic/tkUtil.c
index 1e9c334..da2ce95 100644
--- a/generic/tkUtil.c
+++ b/generic/tkUtil.c
@@ -1196,7 +1196,8 @@ Tk_SendVirtualEvent(
     Tk_QueueWindowEvent(&event.general, TCL_QUEUE_TAIL);
 }
 
-#if TCL_UTF_MAX <= 4
+/* Tcl 8.6 has a different definition of Tcl_UniChar than other Tcl versions for TCL_UTF_MAX > 3 */
+#if TCL_UTF_MAX <= (3 + (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 6))
 /*
  *---------------------------------------------------------------------------
  *
@@ -1225,15 +1226,10 @@ TkUtfToUniChar(
     Tcl_UniChar uniChar = 0;
 
     size_t len = Tcl_UtfToUniChar(src, &uniChar);
-    if ((sizeof(Tcl_UniChar) == 2)
-	    && ((uniChar & 0xFC00) == 0xD800)
-#if TCL_MAJOR_VERSION > 8
-	    && (len == 1)
-#endif
-	) {
+    if ((uniChar & 0xFC00) == 0xD800) {
 	Tcl_UniChar low = uniChar;
-	/* This can only happen if Tcl is compiled with TCL_UTF_MAX=4,
-	 * or when a high surrogate character is detected in UTF-8 form */
+	/* This can only happen if sizeof(Tcl_UniChar)== 2 and src points
+	 * to a character > U+FFFF  */
 	size_t len2 = Tcl_UtfToUniChar(src+len, &low);
 	if ((low & 0xFC00) == 0xDC00) {
 	    *chPtr = (((uniChar & 0x3FF) << 10) | (low & 0x3FF)) + 0x10000;
@@ -1265,7 +1261,7 @@ TkUtfToUniChar(
 
 size_t TkUniCharToUtf(int ch, char *buf)
 {
-    if ((sizeof(Tcl_UniChar) == 2) && (((unsigned)(ch - 0x10000) <= 0xFFFFF))) {
+    if ((unsigned)(ch - 0x10000) <= 0xFFFFF) {
 	/* Spit out a 4-byte UTF-8 character or 2 x 3-byte UTF-8 characters, depending on Tcl
 	 * version and/or TCL_UTF_MAX build value */
 	int len = Tcl_UniCharToUtf(0xD800 | ((ch - 0x10000) >> 10), buf);
@@ -1273,44 +1269,6 @@ size_t TkUniCharToUtf(int ch, char *buf)
     }
     return Tcl_UniCharToUtf(ch, buf);
 }
-/*
- *---------------------------------------------------------------------------
- *
- * TkUtfPrev --
- *
- *	Almost the same as Tcl_UtfPrev.
- *	This function is capable of jumping over a upper/lower surrogate pair.
- *	So, might jump back up to 6 bytes.
- *
- * Results:
- *	pointer to the first byte of the current UTF-8 character. A surrogate
- *	pair is also handled as being a single entity.
- *
- * Side effects:
- *	None.
- *
- *---------------------------------------------------------------------------
- */
-
-const char *
-TkUtfPrev(
-    const char *src,	/* The UTF-8 string. */
-    const char *start)		/* Start position of string */
-{
-    const char *p = Tcl_UtfPrev(src, start);
-    const char *first = Tcl_UtfPrev(p, start);
-    int ch;
-
-#if TCL_UTF_MAX == 3
-    if ((src - start > 3) && ((src[-1] & 0xC0) == 0x80) && ((src[-2] & 0xC0) == 0x80)
-	    && ((src[-3] & 0xC0) == 0x80) && (UCHAR(src[-4]) >= 0xF0)) {
-	return src - 4;
-    }
-#endif
-
-    return (first + TkUtfToUniChar(first, &ch) >= src) ? first : p ;
-}
-
 #endif
 /*
  * Local Variables: