src,lib: print prinstine source when source map source not found

lib/internal/source_map/prepare_stack_trace.js

@@ -139,17 +139,22 @@ function getErrorSource(
   originalLine,
   originalColumn
 ) {
-  let exceptionLine = '';
+  let exceptionLine;
   const originalSourcePathNoScheme =
     StringPrototypeStartsWith(originalSourcePath, 'file://') ?
       fileURLToPath(originalSourcePath) : originalSourcePath;
   const source = getOriginalSource(
     sourceMap.payload,
     originalSourcePath
   );
+  if (typeof source !== 'string') {
+    return;
+  }
   const lines = RegExpPrototypeSymbolSplit(/\r?\n/, source, originalLine + 1);
   const line = lines[originalLine];
-  if (!line) return exceptionLine;
+  if (!line) {
+    return;
+  }
 
   // Display ^ in appropriate position, regardless of whether tabs or
   // spaces are used:
@@ -184,10 +189,7 @@ function getOriginalSource(payload, originalSourcePath) {
       source = readFileSync(originalSourcePathNoScheme, 'utf8');
     } catch (err) {
       debug(err);
-      source = '';
     }
-  } else {
-    source = '';
   }
   return source;
 }

src/node_errors.cc

@@ -105,7 +105,9 @@ static std::string GetErrorSource(Isolate* isolate,
   if (has_source_map_url && env != nullptr && env->source_maps_enabled()) {
     std::string source = GetSourceMapErrorSource(
         isolate, context, message, added_exception_line);
-    return *added_exception_line ? source : sourceline;
+    if (*added_exception_line) {
+      return source;
+    }
   }
 
   // Because of how node modules work, all scripts are wrapped with a

test/fixtures/source-map/no-source.ts

@@ -0,0 +1,10 @@
+function Throw() {
+  throw new Error('foo');
+}
+
+Throw();
+
+// To recreate:
+//
+// npx tsc --outDir test/fixtures/source-map --sourceMap test/fixtures/source-map/no-source.ts
+// rename the "source.[0]" to "file-not-exists.ts"

test/message/source_map_no_source_file.js

@@ -0,0 +1,6 @@
+// Flags:  --enable-source-maps
+
+'use strict';
+require('../common');
+
+require('../fixtures/source-map/no-source.js');

test/message/source_map_no_source_file.out

@@ -0,0 +1,17 @@
+*no-source.js:2
+    throw new Error('foo');
+    ^
+
+Error: foo
+    at Throw (*file-not-exists.ts:2:9)
+    at Object.<anonymous> (*file-not-exists.ts:5:1)
+    at Module._compile (node:internal/modules/cjs/loader:*)
+    at Module._extensions..js (node:internal/modules/cjs/loader:*)
+    at Module.load (node:internal/modules/cjs/loader:*)
+    at Module._load (node:internal/modules/cjs/loader:*)
+    at Module.require (node:internal/modules/cjs/loader:*)
+    at require (node:internal/modules/cjs/helpers:*)
+    at Object.<anonymous> (*source_map_no_source_file.js:6:1)
+    at Module._compile (node:internal/modules/cjs/loader:*)
+
+Node.js *