PDFBOX-6035: prevent infinite loop

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1927175 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/graphics/shading/PDShadingType4.java

@@ -192,7 +192,8 @@ List<ShadedTriangle> collectTriangles(AffineTransform xform, Matrix matrix)
                             }
                             break;
                         default:
-                            LOG.warn("bad flag: {}", flag);
+                            LOG.warn("bad flag {}, aborting", flag);
+                            eof = true;
                             break;
                         }
                     }

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/graphics/shading/PDTriangleBasedShadingType.java

@@ -197,6 +197,10 @@ protected Vertex readVertex(ImageInputStream input, long maxSrcCoord, long maxSr
                                 PDRange rangeX, PDRange rangeY, PDRange[] colRangeTab,
                                 Matrix matrix, AffineTransform xform) throws IOException
     {
+        if (bitsPerCoordinate <= 0 || numberOfColorComponents <= 0 || bitsPerColorComponent <= 0)
+        {
+            throw new IOException("nothing to read, check bitsPerCoordinate, numberOfColorComponents and bitsPerColorComponent");
+        }
         float[] colorComponentTab = new float[numberOfColorComponents];
         long x = input.readBits(bitsPerCoordinate);
         long y = input.readBits(bitsPerCoordinate);