8262477: Enhance String Conclusions

Reviewed-by: rhalade, mschoene, psadhukhan, jdv, serb

Author: prrace

src/java.desktop/share/classes/sun/font/TrueTypeFont.java

@@ -985,24 +985,36 @@ private void setStyle(ByteBuffer os_2Table) {
 
     private void setStrikethroughMetrics(ByteBuffer os_2Table, int upem) {
         if (os_2Table == null || os_2Table.capacity() < 30 || upem < 0) {
-            stSize = .05f;
-            stPos = -.4f;
+            stSize = 0.05f;
+            stPos = -0.4f;
             return;
         }
         ShortBuffer sb = os_2Table.asShortBuffer();
         stSize = sb.get(13) / (float)upem;
         stPos = -sb.get(14) / (float)upem;
+        if (stSize < 0f) {
+            stSize = 0.05f;
+        }
+        if (Math.abs(stPos) > 2.0f) {
+            stPos = -0.4f;
+        }
     }
 
     private void setUnderlineMetrics(ByteBuffer postTable, int upem) {
         if (postTable == null || postTable.capacity() < 12 || upem < 0) {
-            ulSize = .05f;
-            ulPos = .1f;
+            ulSize = 0.05f;
+            ulPos = 0.1f;
             return;
         }
         ShortBuffer sb = postTable.asShortBuffer();
         ulSize = sb.get(5) / (float)upem;
         ulPos = -sb.get(4) / (float)upem;
+        if (ulSize < 0f) {
+            ulSize = 0.05f;
+        }
+        if (Math.abs(ulPos) > 2.0f) {
+            ulPos = 0.1f;
+        }
     }
 
     @Override