fix(block): adjust trailing diamond color overrides

resolves #3850

.vscode/launch.json

@@ -12,7 +12,8 @@
         "print",
         "primary",
         "--shell=pwsh",
-        "--terminal-width=200"
+        "--terminal-width=200",
+        "--config=/Users/jan/.test.omp.json"
       ]
     },
     {

src/ansi/ansi_writer.go

@@ -54,7 +54,7 @@ const (
 	// Foreground takes the current segment's foreground color
 	Foreground = "foreground"
 
-	anchorRegex    = `^(?P<ANCHOR><(?P<FG>[^,>]+)?,?(?P<BG>[^>]+)?>)`
+	AnchorRegex    = `^(?P<ANCHOR><(?P<FG>[^,>]+)?,?(?P<BG>[^>]+)?>)`
 	colorise       = "\x1b[%sm"
 	transparent    = "\x1b[0m\x1b[%s;49m\x1b[7m"
 	transparentEnd = "\x1b[27m"
@@ -288,7 +288,7 @@ func (w *Writer) Write(background, foreground, text string) {
 		w.foreground = w.AnsiColors.ToColor("white", false, w.TrueColor)
 	}
 	// validate if we start with a color override
-	match := regex.FindNamedRegexMatch(anchorRegex, text)
+	match := regex.FindNamedRegexMatch(AnchorRegex, text)
 	if len(match) != 0 {
 		colorOverride := true
 		for _, style := range knownStyles {
@@ -320,7 +320,7 @@ func (w *Writer) Write(background, foreground, text string) {
 
 		// color/end overrides first
 		text = string(w.runes[i:])
-		match = regex.FindNamedRegexMatch(anchorRegex, text)
+		match = regex.FindNamedRegexMatch(AnchorRegex, text)
 		if len(match) > 0 {
 			i = w.writeColorOverrides(match, background, i)
 			continue

src/engine/block.go

@@ -1,11 +1,13 @@
 package engine
 
 import (
+	"strings"
 	"sync"
 	"time"
 
 	"github.com/jandedobbeleer/oh-my-posh/src/ansi"
 	"github.com/jandedobbeleer/oh-my-posh/src/platform"
+	"github.com/jandedobbeleer/oh-my-posh/src/regex"
 	"github.com/jandedobbeleer/oh-my-posh/src/shell"
 )
 
@@ -165,7 +167,11 @@ func (b *Block) writeSeparator(final bool) {
 		b.writer.Write(ansi.Transparent, ansi.Background, b.activeSegment.TrailingDiamond)
 		return
 	}
+
 	isPreviousDiamond := b.previousActiveSegment != nil && b.previousActiveSegment.style() == Diamond
+	if isPreviousDiamond {
+		b.adjustTrailingDiamondColorOverrides()
+	}
 	if isPreviousDiamond && isCurrentDiamond && len(b.activeSegment.LeadingDiamond) == 0 {
 		b.writer.Write(ansi.Background, ansi.ParentBackground, b.previousActiveSegment.TrailingDiamond)
 		return
@@ -201,6 +207,50 @@ func (b *Block) writeSeparator(final bool) {
 	b.writer.Write(bgColor, b.getPowerlineColor(), symbol)
 }
 
+func (b *Block) adjustTrailingDiamondColorOverrides() {
+	// as we now already adjusted the activeSegment, we need to change the value
+	// of background and foreground to parentBackground and parentForeground
+	// this will still break when using parentBackground and parentForeground as keywords
+	// in a trailing diamond, but let's fix that when it happens as it requires either a rewrite
+	// of the logic for diamonds or storing grandparents as well like one happy family.
+	if b.previousActiveSegment == nil || len(b.previousActiveSegment.TrailingDiamond) == 0 {
+		return
+	}
+
+	if !strings.Contains(b.previousActiveSegment.TrailingDiamond, ansi.Background) && !strings.Contains(b.previousActiveSegment.TrailingDiamond, ansi.Foreground) {
+		return
+	}
+
+	match := regex.FindNamedRegexMatch(ansi.AnchorRegex, b.previousActiveSegment.TrailingDiamond)
+	if len(match) == 0 {
+		return
+	}
+
+	adjustOverride := func(anchor, override string) {
+		newOverride := override
+		switch override {
+		case ansi.Foreground:
+			newOverride = ansi.ParentForeground
+		case ansi.Background:
+			newOverride = ansi.ParentBackground
+		}
+
+		if override == newOverride {
+			return
+		}
+
+		newAnchor := strings.Replace(match[ansi.ANCHOR], override, newOverride, 1)
+		b.previousActiveSegment.TrailingDiamond = strings.Replace(b.previousActiveSegment.TrailingDiamond, anchor, newAnchor, 1)
+	}
+
+	if len(match[ansi.BG]) > 0 {
+		adjustOverride(match[ansi.ANCHOR], match[ansi.BG])
+	}
+	if len(match[ansi.FG]) > 0 {
+		adjustOverride(match[ansi.ANCHOR], match[ansi.FG])
+	}
+}
+
 func (b *Block) getPowerlineColor() string {
 	if b.previousActiveSegment == nil {
 		return ansi.Transparent