Build with I/O fixes

build/jsroot.js

@@ -11,7 +11,7 @@ const version_id = 'dev',
 
 /** @summary version date
   * @desc Release date in format day/month/year like '14/04/2022' */
-version_date = '30/07/2024',
+version_date = '2/08/2024',
 
 /** @summary version id and date
   * @desc Produced by concatenation of {@link version_id} and {@link version_date}
@@ -100098,7 +100098,7 @@ class TFile {
      * @private */
    async readKeys() {
       // with the first readbuffer we read bigger amount to create header cache
-      return this.readBuffer([0, 1024]).then(blob => {
+      return this.readBuffer([0, 400]).then(blob => {
          const buf = new TBuffer(blob, 0, this);
          if (buf.substring(0, 4) !== 'root')
             return Promise.reject(Error(`Not a ROOT file ${this.fURL}`));
@@ -100433,6 +100433,11 @@ function readMapElement(buf) {
    }
 
    const n = buf.ntoi4(), res = new Array(n);
+
+   // no extra data written for empty map
+   if (n === 0)
+      return res;
+
    if (this.member_wise && (buf.remain() >= 6)) {
       if (buf.ntoi2() === kStreamedMemberWise)
          buf.shift(4); // skip checksum

changes.md

@@ -19,6 +19,8 @@
 16. Fix - properly save zoomed ranges in drawingJSON()
 17. Fix - properly redraw TMultuGraph
 18. Fix - show empty bin in TProfile2D if it has entries #316
+19. Fix - correctly handle in I/O empty std::map
+20. Fix - reading of small (<1KB) ROOT files
 
 
 ## Changes in 7.7.2

modules/core.mjs

@@ -4,7 +4,7 @@ const version_id = 'dev',
 
 /** @summary version date
   * @desc Release date in format day/month/year like '14/04/2022' */
-version_date = '30/07/2024',
+version_date = '2/08/2024',
 
 /** @summary version id and date
   * @desc Produced by concatenation of {@link version_id} and {@link version_date}