2 files changed, 53 insertions, 46 deletions

diff --git a/generic/tkOption.c b/generic/tkOption.c
index 680c9db..24e7fb3 100644
--- a/generic/tkOption.c
+++ b/generic/tkOption.c
@@ -1080,10 +1080,10 @@ ReadOptionFile(
 				 * TK_MAX_PRIO. */
 {
     const char *realName;
-    char *buffer;
+    Tcl_Obj *buffer;
     int result, bufferSize;
     Tcl_Channel chan;
-    Tcl_DString newName, optString;
+    Tcl_DString newName;
 
     /*
      * Prevent file system access in a safe interpreter.
@@ -1108,24 +1108,10 @@ ReadOptionFile(
 	return TCL_ERROR;
     }
 
-    /*
-     * Compute size of file by seeking to the end of the file. This will
-     * overallocate if we are performing CRLF translation.
-     */
-
-    bufferSize = (int) Tcl_Seek(chan, (Tcl_WideInt) 0, SEEK_END);
-    Tcl_Seek(chan, (Tcl_WideInt) 0, SEEK_SET);
-
-    if (bufferSize < 0) {
-	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-		"error seeking to end of file \"%s\": %s",
-		fileName, Tcl_PosixError(interp)));
-	Tcl_Close(NULL, chan);
-	return TCL_ERROR;
-    }
-
-    buffer = ckalloc(bufferSize + 1);
-    bufferSize = Tcl_Read(chan, buffer, bufferSize);
+    buffer = Tcl_NewObj();
+    Tcl_IncrRefCount(buffer);
+    Tcl_SetChannelOption(NULL, chan, "-encoding", "utf-8");
+    bufferSize = Tcl_ReadChars(chan, buffer, -1, 0);
     if (bufferSize < 0) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"error reading file \"%s\": %s",
@@ -1134,18 +1120,8 @@ ReadOptionFile(
 	return TCL_ERROR;
     }
     Tcl_Close(NULL, chan);
-    buffer[bufferSize] = 0;
-    if ((bufferSize>2) && !memcmp(buffer, "\357\273\277", 3)) {
-	/* File starts with UTF-8 BOM */
-	result = AddFromString(interp, tkwin, buffer+3, priority);
-    } else {
-	Tcl_DStringInit(&optString);
-	Tcl_ExternalToUtfDString(NULL, buffer, bufferSize, &optString);
-	result = AddFromString(interp, tkwin, Tcl_DStringValue(&optString),
-		priority);
-	Tcl_DStringFree(&optString);
-    }
-    ckfree(buffer);
+    result = AddFromString(interp, tkwin, Tcl_GetString(buffer), priority);
+    Tcl_DecrRefCount(buffer);
     return result;
 }
 
diff --git a/generic/tkTextDisp.c b/generic/tkTextDisp.c
index 18b373f..7969091 100644
--- a/generic/tkTextDisp.c
+++ b/generic/tkTextDisp.c
@@ -4869,16 +4869,9 @@ TextRedrawTag(
 
     /*
      * Round up the starting position if it's before the first line visible on
-     * the screen (we only care about what's on the screen). Beware that the
-     * display info structure might need update, for instance if we arrived
-     * here from an 'after idle' script removing tags in a range whose
-     * display lines (and dInfo) were partially invalidated by a previous
-     * delete operation in the text widget.
+     * the screen (we only care about what's on the screen).
      */
 
-    if (dInfoPtr->flags & DINFO_OUT_OF_DATE) {
-	UpdateDisplayInfo(textPtr);
-    }
     dlPtr = dInfoPtr->dLinePtr;
     if (dlPtr == NULL) {
 	return;
@@ -5240,7 +5233,10 @@ TkTextSetYView(
 
                     dInfoPtr->newTopPixelOffset = 0;
                     goto scheduleUpdate;
-	            }
+                }
+                /*
+                 * The line is already on screen, with no need to scroll.
+                 */
                 return;
             }
         }
@@ -6703,6 +6699,7 @@ FindDLine(
     const TkTextIndex *indexPtr)/* Index of desired character. */
 {
     DLine *dlPtrPrev;
+    TkTextIndex indexPtr2;
 
     if (dlPtr == NULL) {
 	return NULL;
@@ -6727,24 +6724,58 @@ FindDLine(
         dlPtrPrev = dlPtr;
         dlPtr = dlPtr->nextPtr;
         if (dlPtr == NULL) {
-            TkTextIndex indexPtr2;
             /*
              * We're past the last display line, either because the desired
              * index lies past the visible text, or because the desired index
-             * is on the last display line showing the last logical line.
+             * is on the last display line.
              */
             indexPtr2 = dlPtrPrev->index;
             TkTextIndexForwBytes(textPtr, &indexPtr2, dlPtrPrev->byteCount,
                     &indexPtr2);
             if (TkTextIndexCmp(&indexPtr2,indexPtr) > 0) {
+                /*
+                 * The desired index is on the last display line.
+                 * --> return this display line.
+                 */
                 dlPtr = dlPtrPrev;
-                break;
             } else {
-                return NULL;
+                /*
+                 * The desired index is past the visible text. There is no
+                 * display line displaying something at the desired index.
+                 * --> return NULL.
+                 */
             }
+            break;
         }
         if (TkTextIndexCmp(&dlPtr->index,indexPtr) > 0) {
-            dlPtr = dlPtrPrev;
+            /*
+             * If we're here then we would normally expect that:
+             *   dlPtrPrev->index  <=  indexPtr  <  dlPtr->index
+             * i.e. we have found the searched display line being dlPtr.
+             * However it is possible that some DLines were unlinked
+             * previously, leading to a situation where going through
+             * the list of display lines skips display lines that did
+             * exist just a moment ago.
+             */
+            indexPtr2 = dlPtrPrev->index;
+            TkTextIndexForwBytes(textPtr, &indexPtr2, dlPtrPrev->byteCount,
+                    &indexPtr2);
+            if (TkTextIndexCmp(&indexPtr2,indexPtr) > 0) {
+                /*
+                 * Confirmed:
+                 *   dlPtrPrev->index  <=  indexPtr  <  dlPtr->index
+                 * --> return dlPtrPrev.
+                 */
+                dlPtr = dlPtrPrev;
+            } else {
+                /*
+                 * The last (rightmost) index shown by dlPtrPrev is still
+                 * before the desired index. This may be because there was
+                 * previously a display line between dlPtrPrev and dlPtr
+                 * and this display line has been unlinked.
+                 * --> return dlPtr.
+                 */
+            }
             break;
         }
     }