[flang][runtime] Fix formatted input of NAN(...)

Formatted real input is allowed to have parenthesized information
after "NAN".  We don't interpret the contents, but we should at
least scan the information correctly.

Fixes #149533 and
#150035.

Author: klausler

flang-rt/lib/runtime/edit-input.cpp

@@ -375,21 +375,37 @@ static RT_API_ATTRS ScannedRealInput ScanRealInput(
         Put(*next);
       }
     }
-    if (next && *next == '(') { // NaN(...)
-      Put('(');
-      int depth{1};
-      while (true) {
-        next = io.NextInField(remaining, edit);
-        if (depth == 0) {
-          break;
-        } else if (!next) {
-          return {}; // error
-        } else if (*next == '(') {
-          ++depth;
-        } else if (*next == ')') {
-          --depth;
+    if (first == 'N' && (!next || *next == '(') &&
+        remaining.value_or(1) > 0) { // NaN(...)?
+      std::size_t byteCount{0};
+      if (!next) { // NextInField won't return '(' for list-directed
+        next = io.GetCurrentChar(byteCount);
+      }
+      if (next && *next == '(') {
+        int depth{1};
+        while (true) {
+          if (*next >= 'a' && *next <= 'z') {
+            *next = *next - 'a' + 'A';
+          }
+          Put(*next);
+          io.HandleRelativePosition(byteCount);
+          io.GotChar(byteCount);
+          if (remaining) {
+            *remaining -= byteCount;
+          }
+          if (depth == 0) {
+            break; // done
+          }
+          next = io.GetCurrentChar(byteCount);
+          if (!next || remaining.value_or(1) < 1) {
+            return {}; // error
+          } else if (*next == '(') {
+            ++depth;
+          } else if (*next == ')') {
+            --depth;
+          }
         }
-        Put(*next);
+        next = io.NextInField(remaining, edit);
       }
     }
   } else if (first == radixPointChar || (first >= '0' && first <= '9') ||

flang-rt/unittests/Runtime/NumericalFormatTest.cpp

@@ -964,6 +964,7 @@ TEST(IOApiTests, EditDoubleInputValues) {
       {"(RU,E9.1)", " 1.0E-325", 0x1, 0},
       {"(E9.1)", "-1.0E-325", 0x8000000000000000, 0},
       {"(RD,E9.1)", "-1.0E-325", 0x8000000000000001, 0},
+      {"(F7.0))", "+NaN(q)", 0x7ff8000000000000, 0},
   };
   for (auto const &[format, data, want, iostat] : testCases) {
     auto cookie{IONAME(BeginInternalFormattedInput)(