From 3652e3627ab06f9a2d436b575162753e750939e7 Mon Sep 17 00:00:00 2001
From: Vaibhav Sharma <48472541+GhostVaibhav@users.noreply.github.com>
Date: Tue, 23 Jul 2024 18:59:33 +0530
Subject: [PATCH] [AdvPaste]Fix CSV parser supporting escape delimiter by
 enclosing in double quotes (#33874)

## Summary of the Pull Request
This PR fixes the CSV parser support for escaping delimiter by enclosing
it in quotes

## Detailed Description of the Pull Request / Additional comments
- This PR introduces a fix for the support of adding a delimiter to the
string and supporting it by enclosing it in `"`
---
 .github/actions/spell-check/expect.txt        |  1 +
 .../AdvancedPaste/Helpers/JsonHelper.cs       | 20 +++++++++++--------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/.github/actions/spell-check/expect.txt b/.github/actions/spell-check/expect.txt
index 27bfb943ab..1299374146 100644
--- a/.github/actions/spell-check/expect.txt
+++ b/.github/actions/spell-check/expect.txt
@@ -1064,6 +1064,7 @@ numberbox
 nwc
 Objbase
 objidl
+occurrence
 ocr
 Ocrsettings
 odbccp
diff --git a/src/modules/AdvancedPaste/AdvancedPaste/Helpers/JsonHelper.cs b/src/modules/AdvancedPaste/AdvancedPaste/Helpers/JsonHelper.cs
index 680308f519..fc23a6de5b 100644
--- a/src/modules/AdvancedPaste/AdvancedPaste/Helpers/JsonHelper.cs
+++ b/src/modules/AdvancedPaste/AdvancedPaste/Helpers/JsonHelper.cs
@@ -24,6 +24,9 @@ namespace AdvancedPaste.Helpers
         private static readonly char[] CsvDelimArry = [',', ';', '\t'];
         private static readonly Regex CsvSepIdentifierRegex = new Regex(@"^sep=(.)$", RegexOptions.IgnoreCase);
 
+        // Split on every occurrence of the delimiter except if it is enclosed by " and ignore two " as escaped "
+        private static readonly string CsvDelimSepRegexStr = @"(?=(?:[^""]*""[^""]*"")*(?![^""]*""))";
+
         internal static string ToJsonFromXmlOrCsv(DataPackageView clipboardData)
         {
             Logger.LogTrace();
@@ -146,10 +149,11 @@ namespace AdvancedPaste.Helpers
                             continue;
                         }
 
-                        // A CSV line is valid, if the delimiter occurs more or equal times in every line compared to the first data line. (More because sometimes the delimiter occurs in a data string.)
-                        if (line.Count(x => x == delim) >= delimCount)
+                        // A CSV line is valid, if the delimiter occurs equal times in every line compared to the first data line
+                        // and if every line contains no or an even count of quotation marks.
+                        if (Regex.Count(line, delim + CsvDelimSepRegexStr) == delimCount && int.IsEvenInteger(line.Count(x => x == '"')))
                         {
-                            csv.Add(line.Split(delim));
+                            csv.Add(Regex.Split(line, delim + CsvDelimSepRegexStr, RegexOptions.IgnoreCase));
                         }
                         else
                         {
@@ -205,7 +209,7 @@ namespace AdvancedPaste.Helpers
                     // We get the count from the second line, as the first one only contains the character definition and not a CSV data line.
                     char delimChar = matchChar.Groups[1].Value.Trim()[0];
                     delimiter = delimChar;
-                    delimiterCount = csvLines[1].Count(x => x == delimChar);
+                    delimiterCount = Regex.Count(csvLines[1], delimChar + CsvDelimSepRegexStr, RegexOptions.IgnoreCase);
                 }
             }
 
@@ -214,19 +218,19 @@ namespace AdvancedPaste.Helpers
                 // Try to select the correct delimiter based on the first two CSV lines from a list of predefined delimiters.
                 foreach (char c in CsvDelimArry)
                 {
-                    int cntFirstLine = csvLines[0].Count(x => x == c);
+                    int cntFirstLine = Regex.Count(csvLines[0], c + CsvDelimSepRegexStr, RegexOptions.IgnoreCase);
                     int cntNextLine = 0; // Default to 0 that the 'second line' check is always true.
 
                     // Additional count if we have more than one line
                     if (csvLines.Length >= 2)
                     {
-                        cntNextLine = csvLines[1].Count(x => x == c);
+                        cntNextLine = Regex.Count(csvLines[1], c + CsvDelimSepRegexStr, RegexOptions.IgnoreCase);
                     }
 
                     // The delimiter is found if the count is bigger as from the last selected delimiter
-                    // and if the next csv line does not exist or has the same number or more occurrences of the delimiter.
+                    // and if the next csv line does not exist or has the same number of occurrences of the delimiter.
                     // (We check the next line to prevent false positives.)
-                    if (cntFirstLine > delimiterCount && (cntNextLine == 0 || cntNextLine >= cntFirstLine))
+                    if (cntFirstLine > delimiterCount && (cntNextLine == 0 || cntNextLine == cntFirstLine))
                     {
                         delimiter = c;
                         delimiterCount = cntFirstLine;