[flang] Fix list-directed input (repeated nulls and LOGICAL)

[klausler]

Summary

Allow repeated nulls in list-directed input (e.g., "4*,") and
ignore excess characters in list-directed LOGICAL input after the
T or F.

Fixes FCVS test fm923.f.

flang/runtime/edit-input.cpp

case 'f':
     break;
   default:
     io.GetIoErrorHandler().SignalError(
         "Bad character '%lc' in LOGICAL input field", *next);
     return false;
   }
   if (remaining) { // ignore the rest of the field
     io.HandleRelativePosition(*remaining);
+  } else if (edit.descriptor == DataEdit::ListDirected) {
+    while (io.NextInField(remaining)) { // discard rest of field
+    }
   }
   return true;
 }
 
 // See 13.10.3.1 paragraphs 7-9 in Fortran 2018
 static bool EditDelimitedCharacterInput(
     IoStatementState &io, char *x, std::size_t length, char32_t delimiter) {
   while (true) {

flang/runtime/io-stmt.cpp

ListDirectedStatementState<Direction::Input>::GetNextDataEdit(
   DataEdit edit;
   edit.descriptor = DataEdit::ListDirected;
   edit.repeat = 1; // may be overridden below
   edit.modes = connection.modes;
   if (hitSlash_) { // everything after '/' is nullified
     edit.descriptor = DataEdit::ListDirectedNullValue;
     return edit;
   }
+  char32_t comma{','};
+  if (io.mutableModes().editingFlags & decimalComma) {
+    comma = ';';
+  }
   if (remaining_ > 0 && !realPart_) { // "r*c" repetition in progress
     while (connection.currentRecordNumber > initialRecordNumber_) {
       io.BackspaceRecord();
     }
     connection.HandleAbsolutePosition(initialPositionInRecord_);
     if (!imaginaryPart_) {
       edit.repeat = std::min<int>(remaining_, maxRepeat);
+      auto ch{io.GetNextNonBlank()};
+      if (!ch || *ch == ' ' || *ch == comma) { // "r*" repeated null
+        edit.descriptor = DataEdit::ListDirectedNullValue;
+      }
     }
     remaining_ -= edit.repeat;
     return edit;
   }
   // Skip separators, handle a "r*c" repeat count; see 13.10.2 in Fortran 2018
   auto ch{io.GetNextNonBlank()};
   if (imaginaryPart_) {
     imaginaryPart_ = false;
     if (ch && *ch == ')') {
       io.HandleRelativePosition(1);
       ch = io.GetNextNonBlank();
     }
   } else if (realPart_) {
     realPart_ = false;
     imaginaryPart_ = true;
   }
   if (!ch) {
     return std::nullopt;
   }
   if (*ch == '/') {
     hitSlash_ = true;
     edit.descriptor = DataEdit::ListDirectedNullValue;
     return edit;
   }
-  char32_t comma{','};
-  if (io.mutableModes().editingFlags & decimalComma) {
-    comma = ';';
-  }
   bool isFirstItem{isFirstItem_};
   isFirstItem_ = false;
   if (*ch == comma) {
     if (isFirstItem) {
       edit.descriptor = DataEdit::ListDirectedNullValue;
       return edit;
     }
     // Consume comma & whitespace after previous item.
do {
       }
       r = 10 * r + (*ch - '0');
       io.HandleRelativePosition(1);
       ch = io.GetCurrentChar();
     } while (ch && *ch >= '0' && *ch <= '9');
     if (r > 0 && ch && *ch == '*') { // subtle: r must be nonzero
       io.HandleRelativePosition(1);
       ch = io.GetCurrentChar();
-      if (!ch || *ch == ' ' || *ch == comma || *ch == '/') { // "r*" null
+      if (ch && *ch == '/') { // r*/
+        hitSlash_ = true;
         edit.descriptor = DataEdit::ListDirectedNullValue;
         return edit;
       }
+      if (!ch || *ch == ' ' || *ch == comma) { // "r*" null
+        edit.descriptor = DataEdit::ListDirectedNullValue;
+      }
       edit.repeat = std::min<int>(r, maxRepeat);
       remaining_ = r - edit.repeat;
       initialRecordNumber_ = connection.currentRecordNumber;
       initialPositionInRecord_ = connection.positionInRecord;
     } else { // not a repetition count, just an integer value; rewind
       connection.positionInRecord = start;
     }
   }

flang/unittests/Runtime/list-input.cpp

 using namespace Fortran::runtime;
 using namespace Fortran::runtime::io;
 
 int main() {
   StartTests();
 
   char buffer[4][32];
   int j{0};
-  for (const char *p : {"1 2 2*3  ,", ",6,,8,123*",
+  for (const char *p : {"1 2 2*3  ,", ",6,,8,1*",
            "2*'abcdefghijklmnopqrstuvwxyzABC", "DEFGHIJKLMNOPQRSTUVWXYZ'"}) {
     SetCharacter(buffer[j++], sizeof buffer[0], p);
   }
   for (; j < 4; ++j) {
     SetCharacter(buffer[j], sizeof buffer[0], "");
   }
 
   StaticDescriptor<1> staticDescriptor;