Fix [d9fdfa435d]: Long non-wrapped lines in text widget displayed malformed. Backported a fix from Gregor Cramer from the revised_text branch.

1 files changed, 39 insertions, 21 deletions

diff --git a/unix/tkUnixRFont.c b/unix/tkUnixRFont.c
index cce59a8..d43ed24 100644
--- a/unix/tkUnixRFont.c
+++ b/unix/tkUnixRFont.c
@@ -859,6 +859,10 @@ Tk_DrawChars(
     ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
             Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
+   if (maxCoord <= y) {
+      return; /* nothing to draw */
+   }
+
     if (fontPtr->ftDraw == 0) {
 #if DEBUG_FONTSEL
 	printf("Switch to drawable 0x%x\n", drawable);
@@ -879,7 +883,7 @@ Tk_DrawChars(
 	XftDrawSetClip(fontPtr->ftDraw, tsdPtr->clipRegion);
     }
     nspec = 0;
-    while (numBytes > 0 && x <= maxCoord && y <= maxCoord) {
+    while (numBytes > 0) {
 	XftFont *ftFont;
 	FcChar32 c;
 
@@ -896,19 +900,25 @@ Tk_DrawChars(
 
 	ftFont = GetFont(fontPtr, c, 0.0);
 	if (ftFont) {
-	    specs[nspec].font = ftFont;
+            int cx = x;
+            int cy = y;
+
 	    specs[nspec].glyph = XftCharIndex(fontPtr->display, ftFont, c);
-	    specs[nspec].x = x;
-	    specs[nspec].y = y;
 	    XftGlyphExtents(fontPtr->display, ftFont, &specs[nspec].glyph, 1,
 		    &metrics);
-	    x += metrics.xOff;
-	    y += metrics.yOff;
-	    nspec++;
-	    if (nspec == NUM_SPEC) {
-		XftDrawGlyphFontSpec(fontPtr->ftDraw, xftcolor,
-			specs, nspec);
-		nspec = 0;
+            if ((x += metrics.xOff) >= maxCoord
+                  || (y += metrics.yOff) >= maxCoord) {
+               break;
+            }
+            if (metrics.xOff > 0 && cx >= 0 && cy >= 0) {
+               specs[nspec].font = ftFont;
+               specs[nspec].x = cx;
+               specs[nspec].y = cy;
+               if (++nspec == NUM_SPEC) {
+                   XftDrawGlyphFontSpec(fontPtr->ftDraw, xftcolor,
+                           specs, nspec);
+                   nspec = 0;
+               }
 	    }
 	}
     }
@@ -1011,8 +1021,7 @@ TkDrawAngledChars(
     currentFtFont = NULL;
     originX = originY = 0;		/* lint */
 
-    while (numBytes > 0 && x <= maxCoord && x >= minCoord && y <= maxCoord
-	    && y >= minCoord) {
+    while (numBytes > 0 && x >= minCoord && y >= minCoord) {
 	XftFont *ftFont;
 	FcChar32 c;
 
@@ -1050,8 +1059,17 @@ TkDrawAngledChars(
 		XftGlyphExtents(fontPtr->display, currentFtFont, glyphs,
 			nglyph, &metrics);
 		nglyph = 0;
-		x += metrics.xOff;
-		y += metrics.yOff;
+                /*
+                 * Breaking at this place is sub-optimal, but the whole algorithm
+                 * has a design problem, the choice of NUM_SPEC is arbitrary, and so
+                 * the inter-glyph spacing will look arbitrary. This algorithm
+                 * has to draw the whole string at once (or whole blocks with same
+                 * font), this requires a dynamic 'glyphs' array. In case of overflow
+                 * the array has to be divided until the maximal string will fit. (GC)
+                 */
+                if ((x += metrics.xOff) >= maxCoord || (y += metrics.yOff) >= maxCoord) {
+                   break;
+                }
 	    }
 	    currentFtFont = ftFont;
 	}
@@ -1087,8 +1105,7 @@ TkDrawAngledChars(
 	XftDrawSetClip(fontPtr->ftDraw, tsdPtr->clipRegion);
     }
     nspec = 0;
-    while (numBytes > 0 && x <= maxCoord && x >= minCoord
-	    && y <= maxCoord && y >= minCoord) {
+    while (numBytes > 0 && x >= minCoord && y >= minCoord) {
 	XftFont *ftFont, *ft0Font;
 	FcChar32 c;
 
@@ -1112,10 +1129,11 @@ TkDrawAngledChars(
 	    specs[nspec].y = ROUND16(y);
 	    XftGlyphExtents(fontPtr->display, ft0Font, &specs[nspec].glyph, 1,
 		    &metrics);
-	    x += metrics.xOff*cosA + metrics.yOff*sinA;
-	    y += metrics.yOff*cosA - metrics.xOff*sinA;
-	    nspec++;
-	    if (nspec == NUM_SPEC) {
+            if ((x += metrics.xOff*cosA + metrics.yOff*sinA) > maxCoord
+                                 || (y += metrics.yOff*cosA - metrics.xOff*sinA) > maxCoord) {
+               break;
+            }
+            if (++nspec == NUM_SPEC) {
 		XftDrawGlyphFontSpec(fontPtr->ftDraw, xftcolor,
 			specs, nspec);
 		nspec = 0;