Closes #1384. fread handles empty lines with just spaces correctly.

README.md

@@ -49,6 +49,8 @@
 
   12. `merge.data.table` always resets class to `c("data.table", "data.frame")` in result to be consistent with `merge.data.frame`, [#1378](https://github.com/Rdatatable/data.table/issues/1378). Thanks @ladida771.
 
+  13. `fread` reads text input with empty newline but with just spaces properly, for e.g., fread('a,b\n1,2\n   '), [#1384](https://github.com/Rdatatable/data.table/issues/1384). Thanks to @ladida771.
+
 #### NOTES
 
 

inst/tests/tests.Rraw

@@ -7047,6 +7047,11 @@ test(1571, names(tstrsplit(X$a, "", fixed=TRUE, give.names=TRUE)), paste("V", 1:
 test(1572, fread('"abcd efgh." ijkl.\tmnop "qrst uvwx."\t45\n', quote=""), 
            setDT(read.table(text='"abcd efgh." ijkl.\tmnop "qrst uvwx."\t45\n', sep="\t", stringsAsFactors=FALSE, quote="")))
 
+# Fix for #1384, fread with empty new line, initial checks failed due to extra spaces.
+test(1573, fread('a,b
+       1,2
+       '), data.table(a=1L, b=2L))
+
 ##########################
 
 

src/fread.c

@@ -984,7 +984,7 @@ SEXP readfile(SEXP input, SEXP separg, SEXP nrowsarg, SEXP headerarg, SEXP nastr
         case 1: ch = pos + 1*(eof-pos)/3;  str="+ middle";  break;
         case 2: ch = pos + 2*(eof-pos)/3;  str="+   last";  break;  // 2/3 way through rather than end ... easier
         }
-        if (j) {  
+        if (j) {
             // we may have landed inside quoted field containing embedded sep and/or embedded \n
             // find next \n and see if 5 good lines follow. If not try next \n, and so on, until we find the real \n
             // We don't know which line number this is because we jumped straight to it
@@ -1041,6 +1041,7 @@ SEXP readfile(SEXP input, SEXP separg, SEXP nrowsarg, SEXP headerarg, SEXP nastr
             }
             while (ch<eof && *ch!=eol) ch++;
             if (ch<eof && *ch==eol) ch+=eolLen;
+            if (stripWhite) skip_spaces();
         }
         if (verbose) { Rprintf("Type codes (%s 5 rows): ",str); for (i=0; i<ncol; i++) Rprintf("%d",type[i]); Rprintf("\n"); }
     }