Re-integrate the tentative fixes for font-24.5 ([94cfd2f6] for macOS and [1235434d] for Linux) in the present bugfix branch.

1 files changed, 13 insertions, 3 deletions

diff --git a/unix/tkUnixRFont.c b/unix/tkUnixRFont.c
index 8e0ce55..70aebfa 100644
--- a/unix/tkUnixRFont.c
+++ b/unix/tkUnixRFont.c
@@ -711,9 +711,19 @@ Tk_MeasureChars(
 		    (flags & TK_AT_LEAST_ONE && curByte == 0)) {
 		curX = newX;
 		curByte = newByte;
-	    } else if (flags & TK_WHOLE_WORDS && termX != 0) {
-		curX = termX;
-		curByte = termByte;
+	    } else if (flags & TK_WHOLE_WORDS) {
+		if ((flags & TK_AT_LEAST_ONE) && (termX == 0)) {
+		    /*
+		     * No space was seen before reaching the right
+		     * of the allotted maxLength space, i.e. no word
+		     * boundary. Return the string that fills the
+		     * allotted space, without overfill.
+		     * curX and curByte are already the right ones:
+		     */
+		} else {
+		    curX = termX;
+		    curByte = termByte;
+		}
 	    }
 	    break;
 	}