update CONTRIBUTING.md (fixes #3233 h/t @Akxe)

CHANGELOG.md

@@ -7,6 +7,7 @@ changes may not be included if they are not expected to break existing code.
 * Sheet Visibility for ODS / FODS (h/t @edemaine)
 * HTML DOM ingress support formulae (`data-f`)
 * Proper handling of XLSX encoded entities (h/t @inreoh)
+* Proper handling of invalid DIF sheets that match heuristics (h/t @lowkeyfish)
 
 ## v0.20.3
 

CONTRIBUTING.md

@@ -1,69 +1,74 @@
 # Contributing
 
-The SheetJS Libraries should be free and clear to use in your projects.  In
-order to maintain that, every contributor must be vigilant.
+SheetJS CE should be free and clear to use in your projects. To ensure that
+remains true, each contributor must be vigilant and each contribution must be
+carefully scrutinized from a technical and legal perspective.
 
-There have been many projects in the past that have been very lax regarding
-licensing. We are of the opinion that those are ticking timebombs and that no
-commercial product should depend on them.
+Many commercial products and open source projects have been very lax regarding
+licensing. They are ticking timebombs that no commercial product should use.
 
 
-# Required Reading
+## Required Reading
 
 These are pretty short reads and emphasize the importance of proper licensing:
 
-- https://github.com/jazzband/tablib/issues/114 (discussion of other tools)
+- https://web.archive.org/web/20200916173942/https://github.com/jazzband/tablib/issues/114
 
-- https://web.archive.org/web/20120615223756/http://www.codinghorror.com/blog/2007/04/pick-a-license-any-license.html
+- https://web.archive.org/web/20240909210554/https://github.com/stephen-hardy/xlsx.js/issues/8
 
 
-# Raising Issues
+## Raising Issues
 
-Issues should generally be accompanied by test files.  Since github does not
-support attachments, the best method is to send files to <sheetjs@gmail.com>
-(subject line should contain issue number or message) or to share using some
-storage service.  Unless expressly permitted, any attachments will not be
-shared or included in a test suite (although I will ask :)
+Issues should generally be accompanied by test files. It is strongly recommended
+to use the [issue tracker](https://git.sheetjs.com/sheetjs/sheetjs/issues).
 
-If sending email to a gmail account is problematic, the <dev@sheetjs.com> email
-inbox is self-hosted.
+If they cannot be shared publicly, please send files to <oss@sheetjs.com>
+(subject line should contain issue number or message) or share links to files
+hosted on a storage service. Unless expressly permitted, attachments will not be
+shared outside of SheetJS LLC or included in a test suite.
 
-# Opening Pull Requests
+If a NDA is required, please send an email to <oss@sheetjs.com> with subject
+line "Non-Disclosure Agreemeant Request".
 
-[Squash commits](https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History)
-before opening a pull request, If the pull request addresses documentation or
-demos, add `[ci skip]` in the body or title of the commit message to skip tests.
 
-# Pre-Contribution Checklist
+## Opening Pull Requests
+
+Please raise an issue before opening pull requests. It is easy to solve a
+specific problem without considering the full context or implications.
+
+
+## Pre-Contribution Checklist
 
 Before thinking about contributing, make sure that:
 
 - You are not, nor have ever been, an employee of Microsoft Corporation.
 
 - You have not signed any NDAs or Shared Source Agreements with Microsoft
-  Corporation or a subsidiary
+  Corporation or a subsidiary.
 
 - You have not consulted any existing relevant codebase (if you have, please
   take note of which codebases were consulted).
 
 If you cannot attest to each of these items, the best approach is to raise an
-issue.  If it is a particularly high-priority issue, please drop an email to
-<sheetjs@gmail.com> and it will be prioritized.
+issue. If it is a particularly high-priority issue, please drop an email to
+<support@sheetjs.com> and it will be prioritized.
 
 
-# Intra-Contribution
+## Intra-Contribution
 
 Keep these in mind as you work:
 
-- Your contributions are your original work.  Take note of any resources you
+- Your contributions are your original work. Take note of any resources you
   consult in the process. Be extra careful not to use unlicensed code on the
   Internet or code generated by a large language model or other AI tool.
 
-- You are working on your own time.  Unless they explicitly grant permission,
+- You are working on your own time. Unless they explicitly grant permission,
   your employer may be the ultimate owner of your IP
 
-# Post-Contribution
 
-Before contributions are merged, you will receive an email (at the address
-associated with the git commit) and will be asked to confirm the aforementioned
-items.  Ensure that the email addresses associated with the commits are valid.
+## Post-Contribution
+
+Before certain contributions are merged, you will receive an email (at the
+address associated with the git commit) and will be asked to confirm the
+aforementioned items. Ensure that the email addresses associated with the
+commits are valid.

bits/10_ssf.js

@@ -421,7 +421,11 @@ function hashq(str/*:string*/)/*:string*/ {
 	}
 	return o;
 }
-function rnd(val/*:number*/, d/*:number*/)/*:string*/ { var dd = Math.pow(10,d); return ""+(Math.round(val * dd)/dd); }
+function rnd(val/*:number*/, d/*:number*/)/*:string*/ {
+	var sgn = val < 0 ? -1 : 1;
+	var dd = Math.pow(10,d);
+	return ""+sgn*(Math.round(sgn * val * dd)/dd);
+}
 function dec(val/*:number*/, d/*:number*/)/*:number*/ {
 	var _frac = val - Math.floor(val), dd = Math.pow(10,d);
 	if (d < ('' + Math.round(_frac * dd)).length) return 0;

bits/22_xmlutils.js

@@ -153,7 +153,13 @@ function utf8readb(data) {
 function utf8readc(data) { return Buffer_from(data, 'binary').toString('utf8'); }
 
 var utf8corpus = "foo bar baz\u00e2\u0098\u0083\u00f0\u009f\u008d\u00a3";
-var utf8read = has_buf && (/*#__PURE__*/utf8readc(utf8corpus) == /*#__PURE__*/utf8reada(utf8corpus) && utf8readc || /*#__PURE__*/utf8readb(utf8corpus) == /*#__PURE__*/utf8reada(utf8corpus) && utf8readb) || utf8reada;
+var utf8read = /*#__PURE__*/(function() {
+  if(has_buf) {
+    if(utf8readc(utf8corpus) == utf8reada(utf8corpus)) return utf8readc;
+    if(utf8readb(utf8corpus) == utf8reada(utf8corpus)) return utf8readb;
+  }
+  return utf8reada;
+})();
 
 var utf8write/*:StringConv*/ = has_buf ? function(data) { return Buffer_from(data, 'utf8').toString("binary"); } : function(orig/*:string*/)/*:string*/ {
 	var out/*:Array<string>*/ = [], i = 0, c = 0, d = 0;

bits/40_harb.js

@@ -1138,3 +1138,17 @@ function read_wb_ID(d, opts) {
 	}
 }
 
+function read_wb_TABL(d, opts) {
+	var o = opts || {}, OLD_WTF = !!o.WTF; o.WTF = true;
+	try {
+		var out = DIF.to_workbook(d, o);
+		if(!out || !out.Sheets) throw "DIF bad workbook";
+		var ws = out.Sheets[out.SheetNames[0]];
+		if(!ws || !ws["!ref"]) throw "DIF empty worksheet";
+		o.WTF = OLD_WTF;
+		return out;
+	} catch(e) {
+		o.WTF = OLD_WTF;
+		return PRN.to_workbook(d, opts);
+	}
+}

bits/87_read.js

@@ -99,7 +99,7 @@ function readSync(data/*:RawData*/, opts/*:?ParseOpts*/)/*:Workbook*/ {
 			if(n[1] === 0x49 && n[2] === 0x2a && n[3] === 0x00) throw new Error("TIFF Image File is not a spreadsheet");
 			if(n[1] === 0x44) return read_wb_ID(d, o);
 			break;
-		case 0x54: if(n[1] === 0x41 && n[2] === 0x42 && n[3] === 0x4C) return DIF.to_workbook(d, o); break;
+		case 0x54: if(n[1] === 0x41 && n[2] === 0x42 && n[3] === 0x4C) return read_wb_TABL(d, o); break;
 		case 0x50: return (n[1] === 0x4B && n[2] < 0x09 && n[3] < 0x09) ? read_zip(d, o) : read_prn(data, d, o, str);
 		case 0xEF: return n[3] === 0x3C ? parse_xlml(d, o) : read_prn(data, d, o, str);
 		case 0xFF:

bits/88_write.js

@@ -111,7 +111,7 @@ function write_binary_type(out, opts/*:WriteOpts*/)/*:any*/ {
 
 function writeSyncXLSX(wb/*:Workbook*/, opts/*:?WriteOpts*/) {
 	reset_cp();
-	check_wb(wb);
+	if(!opts || !opts.unsafe) check_wb(wb);
 	var o = dup(opts||{});
 	if(o.cellStyles) { o.cellNF = true; o.sheetStubs = true; }
 	if(o.type == "array") { o.type = "binary"; var out/*:string*/ = (writeSyncXLSX(wb, o)/*:any*/); o.type = "array"; return s2ab(out); }
@@ -120,7 +120,7 @@ function writeSyncXLSX(wb/*:Workbook*/, opts/*:?WriteOpts*/) {
 
 function writeSync(wb/*:Workbook*/, opts/*:?WriteOpts*/) {
 	reset_cp();
-	check_wb(wb);
+	if(!opts || !opts.unsafe) check_wb(wb);
 	var o = dup(opts||{});
 	if(o.cellStyles) { o.cellNF = true; o.sheetStubs = true; }
 	if(o.type == "array") { o.type = "binary"; var out/*:string*/ = (writeSync(wb, o)/*:any*/); o.type = "array"; return s2ab(out); }

types/index.d.ts

@@ -317,6 +317,9 @@ export interface WritingOptions extends CommonOptions {
 
     /** Record Separator ("row separator") for CSV / Text output */
     RS?: string;
+
+    /** Skip certain validity checks (NOTE: generated files may not open in Excel) */
+    unsafe?: boolean;
 }
 
 /** Workbook Object */