fix(datamatrix): return an error instead of panicking past 144x144 capacity

src/datamatrix/encoder/base256_encoder.rs

@@ -53,7 +53,7 @@ impl Encoder for Base256Encoder {
         let dataCount = buffer.chars().count() - 1;
         let lengthFieldSize = 1;
         let currentSize = context.getCodewordCount() + dataCount + lengthFieldSize;
-        context.updateSymbolInfoWithLength(currentSize);
+        context.updateSymbolInfoWithLength(currentSize)?;
         let mustPad = (context
             .getSymbolInfo()
             .ok_or(Exceptions::ILLEGAL_STATE)?

src/datamatrix/encoder/c40_encoder.rs

@@ -64,7 +64,7 @@ impl C40Encoder {
             let unwritten = (buffer.chars().count() / 3) * 2;
 
             let curCodewordCount = context.getCodewordCount() + unwritten;
-            context.updateSymbolInfoWithLength(curCodewordCount);
+            context.updateSymbolInfoWithLength(curCodewordCount)?;
             let available = context
                 .getSymbolInfo()
                 .ok_or(Exceptions::ILLEGAL_STATE)?
@@ -139,7 +139,7 @@ impl C40Encoder {
             let unwritten = (buffer.chars().count() / 3) * 2;
 
             let curCodewordCount = context.getCodewordCount() + unwritten + 1; // +1 for the latch to C40
-            context.updateSymbolInfoWithLength(curCodewordCount);
+            context.updateSymbolInfoWithLength(curCodewordCount)?;
             let available = context
                 .getSymbolInfo()
                 .ok_or(Exceptions::ILLEGAL_STATE)?
@@ -201,7 +201,7 @@ impl C40Encoder {
         let rest = buffer.chars().count() % 3;
 
         let curCodewordCount = context.getCodewordCount() + unwritten;
-        context.updateSymbolInfoWithLength(curCodewordCount);
+        context.updateSymbolInfoWithLength(curCodewordCount)?;
         let available = context
             .getSymbolInfo()
             .ok_or(Exceptions::ILLEGAL_STATE)?

src/datamatrix/encoder/edifact_encoder.rs

@@ -75,7 +75,7 @@ impl EdifactEncoder {
             }
             if count == 1 {
                 //Only an unlatch at the end
-                context.updateSymbolInfo();
+                context.updateSymbolInfo()?;
                 let mut available = context
                     .getSymbolInfo()
                     .ok_or(Exceptions::ILLEGAL_STATE)?
@@ -84,7 +84,7 @@ impl EdifactEncoder {
                 let remaining = context.getRemainingCharacters();
                 // The following two lines are a hack inspired by the 'fix' from https://sourceforge.net/p/barcode4j/svn/221/
                 if remaining > available {
-                    context.updateSymbolInfoWithLength(context.getCodewordCount() + 1);
+                    context.updateSymbolInfoWithLength(context.getCodewordCount() + 1)?;
                     available = context
                         .getSymbolInfo()
                         .ok_or(Exceptions::ILLEGAL_STATE)?
@@ -105,7 +105,7 @@ impl EdifactEncoder {
             let mut restInAscii = endOfSymbolReached && restChars <= 2;
 
             if restChars <= 2 {
-                context.updateSymbolInfoWithLength(context.getCodewordCount() + restChars);
+                context.updateSymbolInfoWithLength(context.getCodewordCount() + restChars)?;
                 let available = context
                     .getSymbolInfo()
                     .ok_or(Exceptions::ILLEGAL_STATE)?
@@ -115,7 +115,7 @@ impl EdifactEncoder {
                     restInAscii = false;
                     context.updateSymbolInfoWithLength(
                         context.getCodewordCount() + encoded.chars().count(),
-                    );
+                    )?;
                     //available = context.symbolInfo.dataCapacity - context.getCodewordCount();
                 }
             }

src/datamatrix/encoder/encoder_context.rs

@@ -149,14 +149,14 @@ impl<'a> EncoderContext<'_> {
         &self.symbolInfo
     }
 
-    pub fn updateSymbolInfo(&mut self) {
-        self.updateSymbolInfoWithLength(self.getCodewordCount());
+    pub fn updateSymbolInfo(&mut self) -> Result<()> {
+        self.updateSymbolInfoWithLength(self.getCodewordCount())
     }
 
     /// Update symbol info with the length
     ///
-    /// This function can panic
-    pub fn updateSymbolInfoWithLength(&mut self, len: usize) {
+    /// Returns an error if no symbol can hold `len` data codewords.
+    pub fn updateSymbolInfoWithLength(&mut self, len: usize) -> Result<()> {
         if self.symbolInfo.is_none()
             || len > self.symbolInfo.as_ref().unwrap().getDataCapacity() as usize
         {
@@ -168,11 +168,11 @@ impl<'a> EncoderContext<'_> {
                         &self.minSize,
                         &self.maxSize,
                         true,
-                    )
-                    .unwrap()
-                    .unwrap(),
+                    )?
+                    .ok_or(Exceptions::ILLEGAL_STATE)?,
             );
         }
+        Ok(())
     }
 
     pub fn resetSymbolInfo(&mut self) {

src/datamatrix/encoder/high_level_encoder.rs

@@ -229,7 +229,7 @@ pub fn encodeHighLevelWithDimensionForceC40WithSymbolInfoLookup(
         }
     }
     let len = context.getCodewordCount();
-    context.updateSymbolInfo();
+    context.updateSymbolInfo()?;
     let capacity = context
         .getSymbolInfo()
         .ok_or(Exceptions::ILLEGAL_STATE)?

src/datamatrix/encoder/x12_encoder.rs

@@ -79,7 +79,7 @@ impl X12Encoder {
     }
 
     fn handleEOD(context: &mut EncoderContext, buffer: &mut str) -> Result<()> {
-        context.updateSymbolInfo();
+        context.updateSymbolInfo()?;
         let available = context
             .getSymbolInfo()
             .ok_or(Exceptions::ILLEGAL_STATE)?

tests/github_issues.rs

@@ -842,3 +842,30 @@ fn issue_62_rmqr_r7() {
     );
     assert_eq!(result.getText(), "This is ");
 }
+
+/// <https://github.com/rxing-core/rxing/issues/106>
+///
+/// DataMatrix input that does not fit the largest (144x144) symbol must be
+/// rejected with an error instead of panicking.
+#[cfg(all(feature = "encoders", feature = "datamatrix"))]
+#[test]
+fn issue_106_datamatrix_oversize() {
+    use rxing::{BarcodeFormat, Exceptions, MultiFormatWriter};
+
+    for (fits, too_big) in [
+        ("x".repeat(2335), "x".repeat(2336)),
+        ("9".repeat(3116), "9".repeat(3117)),
+    ] {
+        let matrix = MultiFormatWriter
+            .encode(&fits, &BarcodeFormat::DATA_MATRIX, 0, 0)
+            .expect("largest-symbol input must encode");
+        assert_eq!((matrix.getWidth(), matrix.getHeight()), (144, 144));
+
+        let result = MultiFormatWriter.encode(&too_big, &BarcodeFormat::DATA_MATRIX, 0, 0);
+        assert!(
+            matches!(result, Err(Exceptions::IllegalArgumentException(_))),
+            "oversize input must be rejected: {:?}",
+            result.map(|m| (m.getWidth(), m.getHeight()))
+        );
+    }
+}