Dictd: Support extended Dictd format (--index-keep-orig) with 4 entries in the index

See the dictfmt man:

 --index-keep-orig
    When --utf-8 is specified  headwords  are  lowercased  and  non-
    alphanumeric  characters  are  removed  from it before saving to
    .index  file  in   order   to   simplify   the   search.    When
    --index-keep-orig  option  is  used fourth column is created (if
    necessary) in .index file, and  contains  an  original  headword
    which  is  returned by MATCH command.  This option may be useful
    to prevent converting " AT&T" to " ATT" or to keep proper  nouns
    with uppercased first letter.

dictdfiles.cc

@@ -47,7 +47,7 @@ DEF_EX( exInvalidBase64, "Invalid base64 sequence encountered", Dictionary::Ex )
 enum
 {
   Signature = 0x58444344, // DCDX on little-endian, XDCD on big-endian
-  CurrentFormatVersion = 4 + BtreeIndexing::FormatVersion + Folding::Version
+  CurrentFormatVersion = 5 + BtreeIndexing::FormatVersion + Folding::Version
 };
 
 struct IdxHeader
@@ -55,6 +55,7 @@ struct IdxHeader
   uint32_t signature; // First comes the signature, DCDX
   uint32_t formatVersion; // File format version (CurrentFormatVersion)
   uint32_t wordCount; // Total number of words
+  uint32_t articleCount; // Total number of articles
   uint32_t indexBtreeMaxElements; // Two fields from IndexInfo
   uint32_t indexRootOffset;
   uint32_t langFrom;  // Source language
@@ -98,7 +99,7 @@ public:
   { return map< Dictionary::Property, string >(); }
 
   virtual unsigned long getArticleCount() throw()
-  { return idxHeader.wordCount; }
+  { return idxHeader.articleCount; }
 
   virtual unsigned long getWordCount() throw()
   { return idxHeader.wordCount; }
@@ -263,7 +264,19 @@ sptr< Dictionary::DataRequest > DictdDictionary::getArticle( wstring const & wor
       // After tab1 should be article offset, after tab2 -- article size
 
       uint32_t articleOffset = decodeBase64( string( tab1 + 1, tab2 - tab1 - 1 ) );
-      uint32_t articleSize = decodeBase64( tab2 + 1 );
+
+      char * tab3 = strchr( tab2 + 1, '\t');
+
+      uint32_t articleSize;
+      if ( tab3 )
+      {
+         articleSize = decodeBase64( string( tab2 + 1, tab3 - tab2 - 1 ) );
+      }
+      else
+      {
+        articleSize = decodeBase64( tab2 + 1 );
+      }
+
       string articleText;
 
       char * articleBody = dict_data_read_( dz, articleOffset, articleSize, 0, 0 );
@@ -402,29 +415,39 @@ vector< sptr< Dictionary::Class > > makeDictionaries(
           if ( !indexFile.gets( buf, sizeof( buf ), true ) )
             break;
 
-          // Check that there are exactly two tabs in the record.
+          // Check that there are exactly two or three tabs in the record.
-
-          char * tab = strchr( buf, '\t' );
-
-          if ( !tab || ! ( tab = strchr( tab + 1, '\t' ) ) || strchr( tab + 1, '\t' ) )
-          {
-            DPRINTF( "Warning: incorrect amount of tabs in a line, skipping: %s\n", buf );
-            continue;
-          }
-
-          // Check for proper dictionary name
-          if ( !strncmp( buf, "00databaseshort", 15 ) || !strncmp( buf, "00-database-short", 17 ) )
-          {
           char * tab1 = strchr( buf, '\t' );
           if ( tab1 )
           {
             char * tab2 = strchr( tab1 + 1, '\t' );
             if ( tab2 )
+            {
+              char * tab3 = strchr( tab2 + 1, '\t');
+              if ( tab3 )
+              {
+                char * tab4 = strchr( tab3 + 1, '\t');
+                if ( tab4 )
+                {
+                  DPRINTF( "Warning: too many tabs present, skipping: %s\n", buf );
+                  continue;
+                }
+
+                // Handle the forth entry, if it exists. From dictfmt man:
+                // When --index-keep-orig option is used fourth column is created
+                // (if necessary) in .index file.
+                indexedWords.addWord( Utf8::decode( string( tab3 + 1, strlen ( tab3 + 1 ) ) ), curOffset );
+                ++idxHeader.wordCount;
+              }
+              indexedWords.addWord( Utf8::decode( string( buf, strchr( buf, '\t' ) - buf ) ), curOffset );
+              ++idxHeader.wordCount;
+              ++idxHeader.articleCount;
+
+              // Check for proper dictionary name
+              if ( !strncmp( buf, "00databaseshort", 15 ) || !strncmp( buf, "00-database-short", 17 ) )
               {
                 // After tab1 should be article offset, after tab2 -- article size
                 uint32_t articleOffset = decodeBase64( string( tab1 + 1, tab2 - tab1 - 1 ) );
                 uint32_t articleSize = decodeBase64( tab2 + 1 );
-
                 dictData * dz = dict_data_open( dictFiles[ 1 ].c_str(), 0 );
 
                 if ( dz )
@@ -450,11 +473,18 @@ vector< sptr< Dictionary::Class > > makeDictionaries(
                 }
               }
             }
+            else
+            {
+              DPRINTF( "Warning: only a single tab present, skipping: %s\n", buf );
+              continue;
+            }
+          }
+          else
+          {
+            DPRINTF( "Warning: no tabs present, skipping: %s\n", buf );
+            continue;
           }
 
-          indexedWords.addWord( Utf8::decode( string( buf, strchr( buf, '\t' ) - buf ) ), curOffset );
-
-          ++idxHeader.wordCount;
 
         } while( !indexFile.eof() );