Fix quote tracking in Find-YamlMappingColon and Remove-YamlInlineComment for plain scalars

Quote characters inside plain (unquoted) scalars were incorrectly toggling
quote state, causing colon detection and inline comment stripping to fail for
values like owner's: Bob or name: O'Connor  # comment.

Added inPlain flag to both functions so quote characters only open quoted
regions at token boundaries (position 0, after ': ', after '- '), not mid-token
in plain scalars. Added 5 tests covering apostrophe/double-quote in plain keys,
values, and sequence items with inline comments.

Author: MariusStorhaug

src/functions/private/Find-YamlMappingColon.ps1

@@ -5,7 +5,8 @@
 
         .DESCRIPTION
         The colon must be followed by whitespace or end-of-line for it to be a YAML mapping
-        separator. Colons inside quoted strings are ignored.
+        separator. Colons inside quoted strings are ignored. Quote characters inside plain
+        (unquoted) scalars are treated as literal characters and do not toggle quote state.
     #>
     [CmdletBinding()]
     [OutputType([int])]
@@ -17,16 +18,30 @@
 
     $inSingle = $false
     $inDouble = $false
+    $inPlain  = $false
     for ($i = 0; $i -lt $Content.Length; $i++) {
         $c = $Content[$i]
         if ($c -eq '\' -and $inDouble) { $i++; continue }
-        if ($c -eq "'" -and -not $inDouble) { $inSingle = -not $inSingle; continue }
-        if ($c -eq '"' -and -not $inSingle) { $inDouble = -not $inDouble; continue }
+        if ($c -eq "'" -and -not $inDouble) {
+            if ($inSingle) { $inSingle = $false; continue }
+            if (-not $inPlain) { $inSingle = $true; continue }
+            continue
+        }
+        if ($c -eq '"' -and -not $inSingle) {
+            if ($inDouble) { $inDouble = $false; continue }
+            if (-not $inPlain) { $inDouble = $true; continue }
+            continue
+        }
         if ($c -eq ':' -and -not $inSingle -and -not $inDouble) {
             if ($i -eq $Content.Length - 1) { return $i }
             $next = $Content[$i + 1]
             if ($next -eq ' ' -or $next -eq "`t") { return $i }
         }
+        if (-not $inSingle -and -not $inDouble -and -not $inPlain) {
+            if ($c -ne ' ' -and $c -ne "`t") {
+                $inPlain = $true
+            }
+        }
     }
     return -1
 }

src/functions/private/Remove-YamlInlineComment.ps1

@@ -15,6 +15,7 @@
 
     $inSingle = $false
     $inDouble = $false
+    $inPlain  = $false
     for ($i = 0; $i -lt $Line.Length; $i++) {
         $c = $Line[$i]
         if ($c -eq '\' -and $inDouble) {
@@ -23,11 +24,13 @@
             continue
         }
         if ($c -eq "'" -and -not $inDouble) {
-            $inSingle = -not $inSingle
+            if ($inSingle) { $inSingle = $false; continue }
+            if (-not $inPlain) { $inSingle = $true; continue }
             continue
         }
         if ($c -eq '"' -and -not $inSingle) {
-            $inDouble = -not $inDouble
+            if ($inDouble) { $inDouble = $false; continue }
+            if (-not $inPlain) { $inDouble = $true; continue }
             continue
         }
         if ($c -eq '#' -and -not $inSingle -and -not $inDouble) {
@@ -36,6 +39,24 @@
                 return $Line.Substring(0, $i)
             }
         }
+        # Track plain scalar vs token boundary.
+        if (-not $inSingle -and -not $inDouble -and -not $inPlain) {
+            if ($c -ne ' ' -and $c -ne "`t") {
+                # A '- ' sequence dash is a token boundary, not a plain scalar start.
+                if ($c -eq '-' -and $i + 1 -lt $Line.Length -and $Line[$i + 1] -eq ' ') {
+                    # sequence dash — value after '- ' may be quoted; do not enter plain
+                } else {
+                    $inPlain = $true
+                }
+            }
+        }
+        # Reset $inPlain after mapping separator ': ' to allow value-position quotes.
+        if ($c -eq ':' -and -not $inSingle -and -not $inDouble -and $i + 1 -lt $Line.Length) {
+            $next = $Line[$i + 1]
+            if ($next -eq ' ' -or $next -eq "`t") {
+                $inPlain = $false
+            }
+        }
     }
     return $Line
 }

tests/ConvertFrom-Yaml.Tests.ps1

@@ -670,4 +670,36 @@ key: value
             { $yaml | ConvertFrom-Yaml } | Should -Throw '*tab*'
         }
     }
+
+    Context 'Plain scalars with embedded quotes' {
+        It 'Parses a plain key containing an apostrophe before the colon' {
+            $result = "owner's: Bob" | ConvertFrom-Yaml
+            $result."owner's" | Should -Be 'Bob'
+        }
+
+        It 'Parses a plain value containing an apostrophe with inline comment stripped' {
+            $result = "name: O'Connor  # a comment" | ConvertFrom-Yaml
+            $result.name | Should -Be "O'Connor"
+        }
+
+        It 'Parses a plain key with embedded double-quote before the colon' {
+            $result = 'say"hello: world' | ConvertFrom-Yaml
+            $result.'say"hello' | Should -Be 'world'
+        }
+
+        It 'Strips inline comment when value contains a mid-token double-quote' {
+            $result = 'key: val"ue  # comment' | ConvertFrom-Yaml
+            $result.key | Should -Be 'val"ue'
+        }
+
+        It 'Parses sequence items with apostrophe in plain scalar and inline comment' {
+            $yaml = @'
+- it's fine  # comment
+- also's good
+'@
+            $result = $yaml | ConvertFrom-Yaml -NoEnumerate
+            $result[0] | Should -Be "it's fine"
+            $result[1] | Should -Be "also's good"
+        }
+    }
 }