fix bug misreporting initial cell length if file size < BOM length (3…

… bytes) (#111)

* fix bug in first cell size if file size < BOM length (3 bytes) (issue #110) and add related test

examples/lib/Makefile

@@ -72,7 +72,10 @@ help:
 
 build: simple print_my_column parse_by_chunk pull
 
-test: test-eol
+test: test-eol test-tiny
+
+test-tiny: build/simple${EXE}
+	@[ "`echo '' | $< - 2>&1`" = "" ] && ${TEST_PASS} || ${TEST_FAIL}
 
 test-eol: test-eol-1 test-eol-2 test-eol-3 test-eol-4
 

src/zsv.c

@@ -152,13 +152,16 @@ enum zsv_status zsv_parse_more(struct zsv_scanner *scanner) {
 #endif
     size_t bom_len = strlen(ZSV_BOM);
     scanner->checked_bom = 1;
-    if(scanner->read(scanner->buff.buff, 1, bom_len, scanner->in) == bom_len
+    if((bytes_read = scanner->read(scanner->buff.buff, 1, bom_len, scanner->in)) == bom_len
        && !memcmp(scanner->buff.buff, ZSV_BOM, bom_len)) {
       // have bom. disregard what we just read
       bytes_read = scanner->read(scanner->buff.buff, 1, capacity, scanner->in);
       scanner->had_bom = 1;
-    } else // no BOM. keep the bytes we just read
-      bytes_read = bom_len + scanner->read(scanner->buff.buff + bom_len, 1, capacity - bom_len, scanner->in);
+    } else { // no BOM. keep the bytes we just read
+      // bytes_read = bom_len + scanner->read(scanner->buff.buff + bom_len, 1, capacity - bom_len, scanner->in);
+      if(bytes_read == bom_len) // maybe we only read < 3 bytes
+        bytes_read += scanner->read(scanner->buff.buff + bom_len, 1, capacity - bom_len, scanner->in);
+    }
   } else // already checked bom. read as usual
     bytes_read = scanner->read(scanner->buff.buff + scanner->partial_row_length, 1,
                                capacity, scanner->in);