Fixing issue #1831 (#1879)

* throw a more explicit exception when trying to PDF417/TEXT encode something outside of 0...255

* refactor PDF417HighLevelEncoder to avoid code duplication
extend UT to new method PDF417HighLevelEncoder#checkCharset

* fix javadoc typo
make UT more stringent on PDF417HighLevelEncoder#checkCharset

* restrict TEXT to 0...127
test with CP437 and Greek chars

* reinstate testEncodeAuto UT

* refactor testEncodeAuto UT

* address codacy findings

* formatting

* fix issue #1831
make PDF417#determineDimensions to enable finer UT
add UT coverage to validate fix for #1831

* fix javadoc for PDF417#determineDimensions
remove stacktrace when UT fails

* make UT Java 8 compliant

1 files changed, 14 insertions, 4 deletions

diff --git a/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417.java b/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417.java
index a9d63dc23..3402bb3d1 100644
--- a/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417.java
+++ b/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417.java
@@ -659,7 +659,8 @@ public final class PDF417 {
     String highLevel = PDF417HighLevelEncoder.encodeHighLevel(msg, compaction, encoding, autoECI);
     int sourceCodeWords = highLevel.length();
 
-    int[] dimension = determineDimensions(sourceCodeWords, errorCorrectionCodeWords);
+    int[] dimension = determineDimensions(minCols, maxCols, minRows, maxRows, 
+        sourceCodeWords, errorCorrectionCodeWords);
 
     int cols = dimension[0];
     int rows = dimension[1];
@@ -692,16 +693,25 @@ public final class PDF417 {
    * Determine optimal nr of columns and rows for the specified number of
    * codewords.
    *
+   * @param minCols minimum number of columns
+   * @param maxCols maximum number of columns
+   * @param minRows minimum number of rows
+   * @param maxRows maximum number of rows
    * @param sourceCodeWords number of code words
    * @param errorCorrectionCodeWords number of error correction code words
    * @return dimension object containing cols as width and rows as height
+   * @throws WriterException when dimensions can't be determined
    */
-  private int[] determineDimensions(int sourceCodeWords, int errorCorrectionCodeWords) throws WriterException {
+  protected static int[] determineDimensions(int minCols, int maxCols,
+      int minRows, int maxRows,
+      int sourceCodeWords, int errorCorrectionCodeWords) throws WriterException {
     float ratio = 0.0f;
     int[] dimension = null;
+    int currentCol = minCols;
 
     for (int cols = minCols; cols <= maxCols; cols++) {
-
+      currentCol = cols;
+      
       int rows = calculateNumberOfRows(sourceCodeWords, errorCorrectionCodeWords, cols);
 
       if (rows < minRows) {
@@ -725,7 +735,7 @@ public final class PDF417 {
 
     // Handle case when min values were larger than necessary
     if (dimension == null) {
-      int rows = calculateNumberOfRows(sourceCodeWords, errorCorrectionCodeWords, minCols);
+      int rows = calculateNumberOfRows(sourceCodeWords, errorCorrectionCodeWords, currentCol);
       if (rows < minRows) {
         dimension = new int[]{minCols, minRows};
       }