BIND 10 trac2369, updated. eb92bed532b40a0904f8397ba108d96f152abbbf [2369] Distinguish between EOF and failures in getChar()

[BIND 10 source code commits]

The branch, trac2369 has been updated
       via  eb92bed532b40a0904f8397ba108d96f152abbbf (commit)
       via  5ac6e8b56caad02994fd9352e3427e975e72f44a (commit)
      from  710bac35169ec02b73a82cab2c4ce31874a8e440 (commit)

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- Log -----------------------------------------------------------------
commit eb92bed532b40a0904f8397ba108d96f152abbbf
Author: Mukund Sivaraman <muks at isc.org>
Date:   Thu Nov 1 10:35:17 2012 +0530

    [2369] Distinguish between EOF and failures in getChar()

commit 5ac6e8b56caad02994fd9352e3427e975e72f44a
Author: Mukund Sivaraman <muks at isc.org>
Date:   Thu Nov 1 10:20:10 2012 +0530

    [2369] Use a const variable's value for END_OF_STREAM state

-----------------------------------------------------------------------

Summary of changes:
 src/lib/dns/master_lexer_inputsource.cc            |   12 +++++++++---
 src/lib/dns/master_lexer_inputsource.h             |   18 +++++++++++++++++-
 .../dns/tests/master_lexer_inputsource_unittest.cc |   12 ++++++------
 3 files changed, 32 insertions(+), 10 deletions(-)

-----------------------------------------------------------------------
diff --git a/src/lib/dns/master_lexer_inputsource.cc b/src/lib/dns/master_lexer_inputsource.cc
index cd23d9c..a747dfb 100644
--- a/src/lib/dns/master_lexer_inputsource.cc
+++ b/src/lib/dns/master_lexer_inputsource.cc
@@ -63,16 +63,22 @@ InputSource::getChar() {
         // getChar(). at_eof_ will be set then. We then simply return
         // early.
         if (at_eof_) {
-            return -1;
+            return (END_OF_STREAM);
         }
         // We are not yet at EOF. Read from the stream.
         int c = input_.get();
         // Have we reached EOF now? If so, set at_eof_ and return early,
         // but don't modify buffer_pos_ (which should still be equal to
         // the size of buffer_).
-        if (!input_.good()) {
+        if (input_.eof()) {
             at_eof_ = true;
-            return -1;
+            return (END_OF_STREAM);
+        }
+        // This has to come after the .eof() check as some
+        // implementations seem to check the eofbit also in .fail().
+        if (input_.fail()) {
+            isc_throw(ReadError,
+                      "Error reading from the input stream: " << getName());
         }
         buffer_.push_back(c);
     }
diff --git a/src/lib/dns/master_lexer_inputsource.h b/src/lib/dns/master_lexer_inputsource.h
index b9ac184..aec5395 100644
--- a/src/lib/dns/master_lexer_inputsource.h
+++ b/src/lib/dns/master_lexer_inputsource.h
@@ -79,8 +79,22 @@ public:
         {}
     };
 
+    /// \brief Exception thrown when we fail to read from the input
+    /// stream or file.
+    struct ReadError : public Unexpected {
+        ReadError(const char* file, size_t line, const char* what) :
+            Unexpected(file, line, what)
+        {}
+    };
+
+    /// \brief Returned by getChar() when end of stream is reached.
+    static const int END_OF_STREAM;
+
     /// \brief Returns a single character from the input source. If end
-    /// of file is reached, -1 is returned.
+    /// of file is reached, \c END_OF_STREAM is returned.
+    ///
+    /// \throws ReadError when reading from the input stream or file
+    /// fails.
     int getChar();
 
     /// \brief Skips backward a single character in the input
@@ -114,6 +128,8 @@ private:
     std::istream& input_;
 };
 
+const int InputSource::END_OF_STREAM = -1;
+
 } // namespace master_lexer_internal
 } // namespace dns
 } // namespace isc
diff --git a/src/lib/dns/tests/master_lexer_inputsource_unittest.cc b/src/lib/dns/tests/master_lexer_inputsource_unittest.cc
index 27426b3..a6876d5 100644
--- a/src/lib/dns/tests/master_lexer_inputsource_unittest.cc
+++ b/src/lib/dns/tests/master_lexer_inputsource_unittest.cc
@@ -71,7 +71,7 @@ TEST_F(InputSourceTest, getAndUngetChar) {
     EXPECT_FALSE(source_.atEOF());
 
     // This should cause EOF to be set.
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
 
     // Now, EOF should be set.
     EXPECT_TRUE(source_.atEOF());
@@ -84,7 +84,7 @@ TEST_F(InputSourceTest, getAndUngetChar) {
     EXPECT_FALSE(source_.atEOF());
 
     // This should cause EOF to be set again.
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
 
     // Now, EOF should be set.
     EXPECT_TRUE(source_.atEOF());
@@ -139,7 +139,7 @@ TEST_F(InputSourceTest, compact) {
     EXPECT_FALSE(source_.atEOF());
 
     // This should cause EOF to be set.
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
 
     // Now, EOF should be set.
     EXPECT_TRUE(source_.atEOF());
@@ -158,7 +158,7 @@ TEST_F(InputSourceTest, compact) {
     // Ungetting here must throw.
     EXPECT_THROW(source_.ungetChar(), InputSource::UngetBeforeBeginning);
 
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
     EXPECT_TRUE(source_.atEOF());
 }
 
@@ -192,7 +192,7 @@ TEST_F(InputSourceTest, compactDuring) {
     EXPECT_FALSE(source_.atEOF());
 
     // This should cause EOF to be set.
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
 
     // Now, EOF should be set.
     EXPECT_TRUE(source_.atEOF());
@@ -212,7 +212,7 @@ TEST_F(InputSourceTest, compactDuring) {
     EXPECT_FALSE(source_.atEOF());
 
     // This should cause EOF to be set.
-    EXPECT_EQ(-1, source_.getChar());
+    EXPECT_EQ(InputSource::END_OF_STREAM, source_.getChar());
 
     // Now, EOF should be set.
     EXPECT_TRUE(source_.atEOF());