sna: Remove special casing of drawing depth=1 glyphs

It turns out that they were not so special after all, and the "fast
path" was missing the important handling such as validating the GC. As a
result we ended up trying to render the glyphs through a planemask of 0
and similar garbage resulting in corruption. An example given by Kaus
Dittrich was the use of rotated glyphs in gnuplot.

Reported-by: Klaus Dittrich
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

2 files changed, 28 insertions, 88 deletions

diff --git a/src/sna/fb/fbgc.c b/src/sna/fb/fbgc.c
index 0969040f..83956c41 100644
--- a/src/sna/fb/fbgc.c
+++ b/src/sna/fb/fbgc.c
@@ -159,6 +159,9 @@ fbValidateGC(GCPtr gc, unsigned long changes, DrawablePtr drawable)
 		mask = FbFullMask(drawable->bitsPerPixel);
 		depthMask = FbFullMask(drawable->depth);
 
+		DBG(("%s: computing rrop mask=%08x, depthMask=%08x, fg=%08x, bg=%08x, planemask=%08x\n",
+		     __FUNCTION__, mask, depthMask, (int)gc->fgPixel, (int)gc->bgPixel, (int)gc->planemask));
+
 		pgc->fg = gc->fgPixel & mask;
 		pgc->bg = gc->bgPixel & mask;
 
@@ -178,6 +181,9 @@ fbValidateGC(GCPtr gc, unsigned long changes, DrawablePtr drawable)
 		pgc->xor = fbXor(gc->alu, pgc->fg, pgc->pm);
 		pgc->bgand = fbAnd(gc->alu, pgc->bg, pgc->pm);
 		pgc->bgxor = fbXor(gc->alu, pgc->bg, pgc->pm);
+
+		DBG(("%s: rrop fg=%08x, bg=%08x, pm=%08x, and=%08x, xor=%08x, bgand=%08x, bgxor=%08x\n",
+		     __FUNCTION__, pgc->fg, pgc->bg, pgc->pm, pgc->and, pgc->xor, pgc->bgand, pgc->bgxor));
 	}
 
 	if (changes & GCDashList) {
diff --git a/src/sna/sna_accel.c b/src/sna/sna_accel.c
index 58fea222..f10eda95 100644
--- a/src/sna/sna_accel.c
+++ b/src/sna/sna_accel.c
@@ -12552,9 +12552,6 @@ sna_poly_text8(DrawablePtr drawable, GCPtr gc,
 	long unsigned i, n;
 	uint32_t fg;
 
-	if (drawable->depth < 8)
-		goto fallback;
-
 	for (i = n = 0; i < count; i++) {
 		if (sna_get_glyph8(gc->font, priv, chars[i], &info[n]))
 			n++;
@@ -12579,22 +12576,22 @@ sna_poly_text8(DrawablePtr drawable, GCPtr gc,
 		return x + extents.overallRight;
 
 	if (FORCE_FALLBACK)
-		goto force_fallback;
+		goto fallback;
 
 	if (!ACCEL_POLY_TEXT8)
-		goto force_fallback;
+		goto fallback;
 
 	if (sna_font_too_large(gc->font))
-		goto force_fallback;
+		goto fallback;
 
 	if (!PM_IS_SOLID(drawable, gc->planemask))
-		goto force_fallback;
+		goto fallback;
 
 	if (!gc_is_solid(gc, &fg))
-		goto force_fallback;
+		goto fallback;
 
 	if (!sna_glyph_blt(drawable, gc, x, y, n, info, &region, fg, -1, true)) {
-force_fallback:
+fallback:
 		DBG(("%s: fallback\n", __FUNCTION__));
 		gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
 				     Linear8Bit, &n, info);
@@ -12615,22 +12612,6 @@ out_gc:
 out:
 	RegionUninit(&region);
 	return x + extents.overallRight;
-
-fallback:
-	DBG(("%s: fallback -- depth=%d\n", __FUNCTION__, drawable->depth));
-	gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
-			     Linear8Bit, &n, info);
-	if (n == 0)
-		return x;
-
-	extents.overallWidth = x;
-	for (i = 0; i < n; i++)
-		extents.overallWidth += info[i]->metrics.characterWidth;
-
-	DBG(("%s: fallback -- fbPolyGlyphBlt\n", __FUNCTION__));
-	fbPolyGlyphBlt(drawable, gc, x, y, n, info, FONTGLYPHS(gc->font));
-
-	return extents.overallWidth;
 }
 
 static int
@@ -12645,9 +12626,6 @@ sna_poly_text16(DrawablePtr drawable, GCPtr gc,
 	long unsigned i, n;
 	uint32_t fg;
 
-	if (drawable->depth < 8)
-		goto fallback;
-
 	for (i = n = 0; i < count; i++) {
 		if (sna_get_glyph16(gc->font, priv, chars[i], &info[n]))
 			n++;
@@ -12672,22 +12650,22 @@ sna_poly_text16(DrawablePtr drawable, GCPtr gc,
 		return x + extents.overallRight;
 
 	if (FORCE_FALLBACK)
-		goto force_fallback;
+		goto fallback;
 
 	if (!ACCEL_POLY_TEXT16)
-		goto force_fallback;
+		goto fallback;
 
 	if (sna_font_too_large(gc->font))
-		goto force_fallback;
+		goto fallback;
 
 	if (!PM_IS_SOLID(drawable, gc->planemask))
-		goto force_fallback;
+		goto fallback;
 
 	if (!gc_is_solid(gc, &fg))
-		goto force_fallback;
+		goto fallback;
 
 	if (!sna_glyph_blt(drawable, gc, x, y, n, info, &region, fg, -1, true)) {
-force_fallback:
+fallback:
 		DBG(("%s: fallback\n", __FUNCTION__));
 		gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
 				     FONTLASTROW(gc->font) ? TwoD16Bit : Linear16Bit,
@@ -12709,23 +12687,6 @@ out_gc:
 out:
 	RegionUninit(&region);
 	return x + extents.overallRight;
-
-fallback:
-	DBG(("%s: fallback -- depth=%d\n", __FUNCTION__, drawable->depth));
-	gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
-			     FONTLASTROW(gc->font) ? TwoD16Bit : Linear16Bit,
-			     &n, info);
-	if (n == 0)
-		return x;
-
-	extents.overallWidth = x;
-	for (i = 0; i < n; i++)
-		extents.overallWidth += info[i]->metrics.characterWidth;
-
-	DBG(("%s: fallback -- fbPolyGlyphBlt\n", __FUNCTION__));
-	fbPolyGlyphBlt(drawable, gc, x, y, n, info, FONTGLYPHS(gc->font));
-
-	return extents.overallWidth;
 }
 
 static void
@@ -12739,9 +12700,6 @@ sna_image_text8(DrawablePtr drawable, GCPtr gc,
 	RegionRec region;
 	long unsigned i, n;
 
-	if (drawable->depth < 8)
-		goto fallback;
-
 	for (i = n = 0; i < count; i++) {
 		if (sna_get_glyph8(gc->font, priv, chars[i], &info[n]))
 			n++;
@@ -12778,20 +12736,20 @@ sna_image_text8(DrawablePtr drawable, GCPtr gc,
 	     region.extents.x2, region.extents.y2));
 
 	if (FORCE_FALLBACK)
-		goto force_fallback;
+		goto fallback;
 
 	if (!ACCEL_IMAGE_TEXT8)
-		goto force_fallback;
+		goto fallback;
 
 	if (sna_font_too_large(gc->font))
-		goto force_fallback;
+		goto fallback;
 
 	if (!PM_IS_SOLID(drawable, gc->planemask))
-		goto force_fallback;
+		goto fallback;
 
 	if (!sna_glyph_blt(drawable, gc, x, y, n, info, &region,
 			   gc->fgPixel, gc->bgPixel, false)) {
-force_fallback:
+fallback:
 		DBG(("%s: fallback\n", __FUNCTION__));
 		gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
 				     Linear8Bit, &n, info);
@@ -12811,16 +12769,6 @@ out_gc:
 	}
 out:
 	RegionUninit(&region);
-	return;
-
-fallback:
-	DBG(("%s: fallback, depth=%d\n", __FUNCTION__, drawable->depth));
-	gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
-			     Linear8Bit, &n, info);
-	if (n) {
-		DBG(("%s: fallback -- fbImageGlyphBlt\n", __FUNCTION__));
-		fbImageGlyphBlt(drawable, gc, x, y, n, info, FONTGLYPHS(gc->font));
-	}
 }
 
 static void
@@ -12834,9 +12782,6 @@ sna_image_text16(DrawablePtr drawable, GCPtr gc,
 	RegionRec region;
 	long unsigned i, n;
 
-	if (drawable->depth < 8)
-		goto fallback;
-
 	for (i = n = 0; i < count; i++) {
 		if (sna_get_glyph16(gc->font, priv, chars[i], &info[n]))
 			n++;
@@ -12873,20 +12818,20 @@ sna_image_text16(DrawablePtr drawable, GCPtr gc,
 	     region.extents.x2, region.extents.y2));
 
 	if (FORCE_FALLBACK)
-		goto force_fallback;
+		goto fallback;
 
 	if (!ACCEL_IMAGE_TEXT16)
-		goto force_fallback;
+		goto fallback;
 
 	if (sna_font_too_large(gc->font))
-		goto force_fallback;
+		goto fallback;
 
 	if (!PM_IS_SOLID(drawable, gc->planemask))
-		goto force_fallback;
+		goto fallback;
 
 	if (!sna_glyph_blt(drawable, gc, x, y, n, info, &region,
 			   gc->fgPixel, gc->bgPixel, false)) {
-force_fallback:
+fallback:
 		DBG(("%s: fallback\n", __FUNCTION__));
 		gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
 				     FONTLASTROW(gc->font) ? TwoD16Bit : Linear16Bit,
@@ -12907,17 +12852,6 @@ out_gc:
 	}
 out:
 	RegionUninit(&region);
-	return;
-
-fallback:
-	DBG(("%s: fallback -- depth=%d\n", __FUNCTION__, drawable->depth));
-	gc->font->get_glyphs(gc->font, count, (unsigned char *)chars,
-			     FONTLASTROW(gc->font) ? TwoD16Bit : Linear16Bit,
-			     &n, info);
-	if (n) {
-		DBG(("%s: fallback -- fbImageGlyphBlt\n", __FUNCTION__));
-		fbImageGlyphBlt(drawable, gc, x, y, n, info, FONTGLYPHS(gc->font));
-	}
 }
 
 /* XXX Damage bypasses the Text interface and so we lose our custom gluphs */