keep non list path

Author: Mukulyadav2004

src/fmelt.c

@@ -600,31 +600,38 @@ SEXP getvarcols(SEXP DT, SEXP dtnames, Rboolean varfactor, Rboolean verbose, str
   if (isNull(data->variable_table)) {
     if (!varfactor) {
       if (data->measure_is_list) {
-        // Return integer indices for list measure.vars (consistency with docs)
         SET_VECTOR_ELT(ansvars, 0, target=allocVector(INTSXP, data->totlen));
         int *td = INTEGER(target);
         for (int j=0, ansloc=0; j<data->lmax; ++j) {
           const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
           for (int k=0; k<thislen; ++k) td[ansloc++] = j+1;
         }
       } else {
-        // same behavior for vector measure.vars: variable is column names
         SET_VECTOR_ELT(ansvars, 0, target=allocVector(STRSXP, data->totlen));
-        const int *thisvaluecols = INTEGER(VECTOR_ELT(data->valuecols, 0));
-        for (int j=0, ansloc=0; j<data->lmax; ++j) {
-          const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
-          SEXP str = STRING_ELT(dtnames, thisvaluecols[j]-1);
-          for (int k=0; k<thislen; ++k) SET_STRING_ELT(target, ansloc++, str);
+        if (data->lvalues == 1) {//one value column to output. 
+          const int *thisvaluecols = INTEGER(VECTOR_ELT(data->valuecols, 0));
+          for (int j=0, ansloc=0; j<data->lmax; ++j) {
+            const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
+            SEXP str = STRING_ELT(dtnames, thisvaluecols[j]-1);
+            for (int k=0; k<thislen; ++k) SET_STRING_ELT(target, ansloc++, str);
+          }
+        } else {
+          for (int j=0, ansloc=0, level=1; j<data->lmax; ++j) {
+            const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
+            char buff[20];
+            snprintf(buff, sizeof(buff), "%d", level++); // # notranslate
+            SEXP s = mkChar(buff);
+            for (int k=0; k<thislen; ++k) SET_STRING_ELT(target, ansloc++, s);
+          }
         }
       }
     } else {// varfactor==TRUE
       SET_VECTOR_ELT(ansvars, 0, target=allocVector(INTSXP, data->totlen));
       SEXP levels;
       int *td = INTEGER(target);
       if (data->measure_is_list) {
-        int nlevel = data->lmax;
-        levels = PROTECT(allocVector(STRSXP, nlevel)); protecti++;
-        for (int j=0; j<nlevel; ++j) {
+        levels = PROTECT(allocVector(STRSXP, data->lmax)); protecti++;
+        for (int j=0; j<data->lmax; ++j) {
           char buff[20];
           snprintf(buff, sizeof(buff), "%d", j+1); // # notranslate
           SET_STRING_ELT(levels, j, mkChar(buff));
@@ -633,8 +640,8 @@ SEXP getvarcols(SEXP DT, SEXP dtnames, Rboolean varfactor, Rboolean verbose, str
           const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
           for (int k=0; k<thislen; ++k) td[ansloc++] = j+1;
         }
-      } else { // non-list measure.vars keeps legacy name-based levels
-        if (data->lvalues == 1) {
+      } else {
+        if (data->lvalues == 1) { // one value column to output
           SEXP thisvaluecols = VECTOR_ELT(data->valuecols, 0);
           int len = length(thisvaluecols);
           levels = PROTECT(allocVector(STRSXP, len)); protecti++;
@@ -644,7 +651,7 @@ SEXP getvarcols(SEXP DT, SEXP dtnames, Rboolean varfactor, Rboolean verbose, str
           int numRemove = 0;  // remove dups and any for which narm and all-NA
           int *md = INTEGER(m);
           for (int j=0; j<len; ++j) {
-            if (md[j]!=j+1 /*dup*/ || (data->narm && length(VECTOR_ELT(data->not_NA_indices, j))==0)) { numRemove++; md[j]=0; }
+            if (md[j]!=j+1 || (data->narm && length(VECTOR_ELT(data->not_NA_indices, j))==0)) { numRemove++; md[j]=0; }
           }
           if (numRemove) {
             SEXP newlevels = PROTECT(allocVector(STRSXP, len-numRemove)); protecti++;
@@ -657,7 +664,7 @@ SEXP getvarcols(SEXP DT, SEXP dtnames, Rboolean varfactor, Rboolean verbose, str
             const int thislen = data->narm ? length(VECTOR_ELT(data->not_NA_indices, j)) : data->nrow;
             for (int k=0; k<thislen; ++k) td[ansloc++] = md[j];
           }
-        } else {//multiple output columns.
+        } else { // multiple output columns
           int nlevel=0;
           levels = PROTECT(allocVector(STRSXP, data->lmax)); protecti++;
           for (int j=0, ansloc=0; j<data->lmax; ++j) {