Port cb0b508: Copy all global subroutines to GSubr INDEX.

DEV-1885

Author: ars18wrw

itext/src/main/java/com/itextpdf/text/pdf/CFFFontSubset.java

@@ -484,7 +484,7 @@ else if (fonts[Font].privateSubrs>=0)
 			// Builds the New Local Subrs index
 			NewSubrsIndexNonCID = BuildNewIndex(fonts[Font].SubrsOffsets,hSubrsUsedNonCID,RETURN_OP);
 		//Builds the New Global Subrs index
-		NewGSubrsIndex = BuildNewIndex(gsubrOffsets,hGSubrsUsed,RETURN_OP);
+		NewGSubrsIndex = BuildNewIndexAndCopyAllGSubrs(gsubrOffsets, RETURN_OP);
 	}
 
 	/**
@@ -980,6 +980,54 @@ protected byte[] BuildNewIndex(int[] Offsets,HashMap<Integer, int[]> Used,byte O
 		return AssembleIndex(NewOffsets,NewObjects);
 	}
 
+	/**
+	 * Function builds the new offset array, object array and assembles the index.
+	 * used for creating the glyph and subrs subsetted index
+	 *
+	 * @param Offsets                  the offset array of the original index
+	 * @param OperatorForUnusedEntries the operator inserted into the data stream for unused entries
+	 * @return the new index subset version
+	 * @throws java.io.IOException
+	 */
+	protected byte[] BuildNewIndexAndCopyAllGSubrs(int[] Offsets, byte OperatorForUnusedEntries) throws java.io.IOException {
+		int unusedCount = 0;
+		int Offset = 0;
+		int[] NewOffsets = new int[Offsets.length];
+		// Build the Offsets Array for the Subset
+		for (int i = 0; i < Offsets.length - 1; ++i) {
+			NewOffsets[i] = Offset;
+			Offset += Offsets[i + 1] - Offsets[i];
+		}
+		// Else the same offset is kept in i+1.
+		NewOffsets[Offsets.length - 1] = Offset;
+		unusedCount++;
+
+		// Offset var determines the size of the object array
+		byte[] NewObjects = new byte[Offset + unusedCount];
+		// Build the new Object array
+		int unusedOffset = 0;
+		for (int i = 0; i < Offsets.length - 1; ++i) {
+			int start = NewOffsets[i];
+			int end = NewOffsets[i + 1];
+			NewOffsets[i] = start + unusedOffset;
+			// If start != End then the Object is used
+			// So, we will copy the object data from the font file
+			if (start != end) {
+				// All offsets are Global Offsets relative to the beginning of the font file.
+				// Jump the file pointer to the start address to read from.
+				buf.seek(Offsets[i]);
+				// Read from the buffer and write into the array at start.
+				buf.readFully(NewObjects, start + unusedOffset, end - start);
+			} else {
+				NewObjects[start + unusedOffset] = OperatorForUnusedEntries;
+				unusedOffset++;
+			}
+		}
+		NewOffsets[Offsets.length - 1] += unusedOffset;
+		// Use AssembleIndex to build the index from the offset & object arrays
+		return AssembleIndex(NewOffsets, NewObjects);
+	}
+
 	/**
 	 * Function creates the new index, inserting the count,offsetsize,offset array
 	 * and object array.