repl: reverse the order of multiline histories

This will make it consistent when loading the new history format with an old node binary

Author: puskin

lib/internal/readline/interface.js

@@ -461,6 +461,15 @@ class Interface extends InterfaceConstructor {
 
   // Convert newlines to a consistent format for history storage
   [kNormalizeHistoryLineEndings](line, from, to) {
+    // Multiline history entries are saved reversed
+    if (StringPrototypeIncludes(line, '\r')) {
+      // First reverse the lines for proper order, then convert separators
+      return ArrayPrototypeJoin(
+        ArrayPrototypeReverse(StringPrototypeSplit(line, from)),
+        to,
+      );
+    }
+    // For normal cases (saving to history or non-multiline entries)
     return StringPrototypeReplaceAll(line, from, to);
   }
 

lib/repl.js

@@ -53,6 +53,7 @@ const {
   ArrayPrototypePop,
   ArrayPrototypePush,
   ArrayPrototypePushApply,
+  ArrayPrototypeReverse,
   ArrayPrototypeShift,
   ArrayPrototypeSlice,
   ArrayPrototypeSome,
@@ -969,7 +970,7 @@ function REPLServer(prompt,
         const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
         self.history = ArrayPrototypeSlice(self.history, lines.length);
         lines[lines.length - 1] = cmd;
-        const newHistoryLine = ArrayPrototypeJoin(lines, '\r');
+        const newHistoryLine = ArrayPrototypeJoin(ArrayPrototypeReverse(lines), '\r');
         if (self.history[0] !== newHistoryLine) {
           ArrayPrototypeUnshift(self.history, newHistoryLine);
         }

test/fixtures/.node_repl_history_multiline

@@ -1,4 +1,4 @@
-var d = [  {    a: 1,    b: 2,  },  {    a: 3,    b: 4,    c: [{ a: 1, b: 2 },      {        a: 3,        b: 4,      }    ]  }]
-const c = [  {    a: 1,    b: 2,  }]
-`const b = [  1,  2,  3,  4,]`
-a = `I am a multiline stringI can be as long as I want`
+]  }    ]      }        b: 4,        a: 3,      {    c: [{ a: 1, b: 2 },    b: 4,    a: 3,  {  },    b: 2,    a: 1,  {var d = [
+]  }    b: 2,    a: 1,  {const c = [
+]`  4,  3,  2,  1,`const b = [
+I can be as long as I want`I am a multiline stringa = `