Index: .github/workflows/linux-build.yml
==================================================================
--- .github/workflows/linux-build.yml
+++ .github/workflows/linux-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-8162e9b7a9"
     tags:
     - "core-**"
 permissions:
   contents: read
 defaults:

Index: .github/workflows/mac-build.yml
==================================================================
--- .github/workflows/mac-build.yml
+++ .github/workflows/mac-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-8162e9b7a9"
     tags:
     - "core-**"
 permissions:
   contents: read
 env:

Index: .github/workflows/win-build.yml
==================================================================
--- .github/workflows/win-build.yml
+++ .github/workflows/win-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-8162e9b7a9"
     tags:
     - "core-**"
 permissions:
   contents: read
 env:

Index: tests/font.test
==================================================================
--- tests/font.test
+++ tests/font.test
@@ -2345,27 +2345,34 @@
     font actual -xyz-?-*-*-*-*-*-*-*-*-*-*-*-*
     lindex [font actual -xyz-times-*-*-*-*-*-*-*-*-*-*-*-*] 1
 } -result [font actual {times 0} -family]
 
 
-test font-44.1 {TkFontGetPixels: size < 0} -setup {
+test font-44.1 {TkFontGetPixels: size < 0}  -setup {
     set oldscale [tk scaling]
 } -body {
-    set oldsize [expr {-(-12.0 / $oldscale)}]
+    # if this test failed, start the investigations by reading ticket [8162e9b7a9]
     tk scaling 0.5
-    expr {round([font actual {times -12} -size] / $oldscale * 0.5) - round($oldsize) == 0}
+    font actual {times -13} -size
 } -cleanup {
     tk scaling $oldscale
-} -result 1
+} -result 26
 test font-44.2 {TkFontGetPoints: size >= 0} -constraints {noExceed haveTimes12Font} -setup {
     set oldscale [tk scaling]
 } -body {
     tk scaling 0.5
     font actual {times 12} -size
 } -cleanup {
     tk scaling $oldscale
 } -result 12
+test font-44.3 {font create with display scaling not 100% - bug 8162e9b7a9} -body {
+    set font1 TkDefaultFont
+    set font2 [font create Font2 {*}[font actual $font1]]
+    expr {[font actual $font1 -size] == [font actual $font2 -size]}
+} -cleanup {
+    font delete $font2
+} -result 1
 
 
 test font-45.1 {TkFontGetAliasList: no match} -body {
     font actual {snarky 10} -family
 } -result [font actual {-size 10} -family]

Index: unix/tkUnixRFont.c
==================================================================
--- unix/tkUnixRFont.c
+++ unix/tkUnixRFont.c
@@ -13,10 +13,20 @@
 #include "tkFont.h"
 #include <X11/Xft/Xft.h>
 
 #define MAX_CACHED_COLORS 16
 
+/*
+ * Debugging support...
+ */
+
+#define DEBUG_FONTSEL 0
+#define DEBUG(arguments) \
+    if (DEBUG_FONTSEL) { \
+	printf arguments; fflush(stdout); \
+    }
+
 typedef struct {
     XftFont *ftFont;
     XftFont *ft0Font;
     FcPattern *source;
     FcCharSet *charset;
@@ -182,23 +192,23 @@
     XftFont *ftFont,
     TkFontAttributes *faPtr)
 {
     const char *family = "Unknown";
     const char *const *familyPtr = &family;
-    int weight, slant, pxsize;
-    double size, ptsize;
+    double ptSize, dblPxSize, size;
+    int intPxSize, weight, slant;
 
     (void) XftPatternGetString(ftFont->pattern, XFT_FAMILY, 0, familyPtr);
-    if (XftPatternGetDouble(ftFont->pattern, XFT_PIXEL_SIZE, 0,
-	    &ptsize) == XftResultMatch) {
-	size = -ptsize;
-    } else if (XftPatternGetDouble(ftFont->pattern, XFT_SIZE, 0,
-	    &ptsize) == XftResultMatch) {
-	size = ptsize;
+    if (XftPatternGetDouble(ftFont->pattern, XFT_SIZE, 0,
+	    &ptSize) == XftResultMatch) {
+	size = ptSize;
+    } else if (XftPatternGetDouble(ftFont->pattern, XFT_PIXEL_SIZE, 0,
+	    &dblPxSize) == XftResultMatch) {
+	size = -dblPxSize;
     } else if (XftPatternGetInteger(ftFont->pattern, XFT_PIXEL_SIZE, 0,
-	    &pxsize) == XftResultMatch) {
-	size = (double)-pxsize;
+	    &intPxSize) == XftResultMatch) {
+	size = (double)-intPxSize;
     } else {
 	size = 12.0;
     }
     if (XftPatternGetInteger(ftFont->pattern, XFT_WEIGHT, 0,
 	    &weight) != XftResultMatch) {
@@ -207,16 +217,18 @@
     if (XftPatternGetInteger(ftFont->pattern, XFT_SLANT, 0,
 	    &slant) != XftResultMatch) {
 	slant = XFT_SLANT_ROMAN;
     }
 
-#ifdef DEBUG_FONTSEL
-    printf("family %s size %d weight %d slant %d\n",
-	    family, (int)size, weight, slant);
-#endif /* DEBUG_FONTSEL */
+    DEBUG(("GetTkFontAttributes: family %s size %ld weight %d slant %d\n",
+	    family, lround(size), weight, slant));
 
     faPtr->family = Tk_GetUid(family);
+    /*
+     * Make sure that faPtr->size will be > 0 even
+     * in the very unprobable case that size < 0
+     */
     faPtr->size = TkFontGetPoints(tkwin, size);
     faPtr->weight = (weight > XFT_WEIGHT_MEDIUM) ? TK_FW_BOLD : TK_FW_NORMAL;
     faPtr->slant = (slant > XFT_SLANT_ROMAN) ? TK_FS_ITALIC : TK_FS_ROMAN;
     faPtr->underline = 0;
     faPtr->overstrike = 0;
@@ -456,13 +468,12 @@
     Tk_Window tkwin,		/* For display where font will be used. */
     const char *name)		/* Platform-specific font name. */
 {
     UnixFtFont *fontPtr;
     FcPattern *pattern;
-#ifdef DEBUG_FONTSEL
-    printf("TkpGetNativeFont %s\n", name);
-#endif /* DEBUG_FONTSEL */
+
+    DEBUG(("TkpGetNativeFont: %s\n", name));
 
     pattern = XftXlfdParse(name, FcFalse, FcFalse);
     if (!pattern) {
 	return NULL;
     }
@@ -494,22 +505,21 @@
 {
     XftPattern *pattern;
     int weight, slant;
     UnixFtFont *fontPtr;
 
-#ifdef DEBUG_FONTSEL
-    printf("TkpGetFontFromAttributes %s-%d %d %d\n", faPtr->family,
-	    (int)faPtr->size, faPtr->weight, faPtr->slant);
-#endif /* DEBUG_FONTSEL */
+    DEBUG(("TkpGetFontFromAttributes: %s %ld %d %d\n", faPtr->family,
+	    lround(faPtr->size), faPtr->weight, faPtr->slant));
+
     pattern = XftPatternCreate();
     if (faPtr->family) {
 	XftPatternAddString(pattern, XFT_FAMILY, faPtr->family);
     }
     if (faPtr->size > 0.0) {
 	XftPatternAddDouble(pattern, XFT_SIZE, faPtr->size);
     } else if (faPtr->size < 0.0) {
-	XftPatternAddDouble(pattern, XFT_PIXEL_SIZE, -faPtr->size);
+	XftPatternAddDouble(pattern, XFT_SIZE, TkFontGetPoints(tkwin, faPtr->size));
     } else {
 	XftPatternAddDouble(pattern, XFT_SIZE, 12.0);
     }
     switch (faPtr->weight) {
     case TK_FW_NORMAL:
@@ -721,11 +731,11 @@
     FcChar32 c;
     XGlyphInfo extents;
     int clen, curX, newX, curByte, newByte, sawNonSpace;
     int termByte = 0, termX = 0, errorFlag = 0;
     Tk_ErrorHandler handler;
-#ifdef DEBUG_FONTSEL
+#if DEBUG_FONTSEL
     char string[256];
     int len = 0;
 #endif /* DEBUG_FONTSEL */
 
     handler = Tk_CreateErrorHandler(fontPtr->display,
@@ -757,11 +767,11 @@
 	    }
 	} else {
 	    sawNonSpace = 1;
 	}
 
-#ifdef DEBUG_FONTSEL
+#if DEBUG_FONTSEL
 	string[len++] = (char) c;
 #endif /* DEBUG_FONTSEL */
 	ftFont = GetFont(fontPtr, c, 0.0);
 
 	if (!errorFlag) {
@@ -800,13 +810,13 @@
 	curX = newX;
 	curByte = newByte;
     }
 measureCharsEnd:
     Tk_DeleteErrorHandler(handler);
-#ifdef DEBUG_FONTSEL
+#if DEBUG_FONTSEL
     string[len] = '\0';
-    printf("MeasureChars %s length %d bytes %d\n", string, curX, curByte);
+    DEBUG(("MeasureChars: %s length %d bytes %d\n", string, curX, curByte));
 #endif /* DEBUG_FONTSEL */
     *lengthPtr = curX;
     return curByte;
 }
 
@@ -938,13 +948,11 @@
     XGlyphInfo metrics;
     ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
             Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
     if (fontPtr->ftDraw == 0) {
-#ifdef DEBUG_FONTSEL
-	printf("Switch to drawable 0x%lx\n", drawable);
-#endif /* DEBUG_FONTSEL */
+	DEBUG(("Switch to drawable 0x%lx\n", drawable));
 	fontPtr->ftDraw = XftDrawCreate(display, drawable,
 		DefaultVisual(display, fontPtr->screen),
 		DefaultColormap(display, fontPtr->screen));
     } else {
 	Tk_ErrorHandler handler =
@@ -1079,13 +1087,11 @@
     XGlyphInfo metrics;
     XftFont *currentFtFont;
     int originX, originY;
 
     if (fontPtr->ftDraw == 0) {
-#ifdef DEBUG_FONTSEL
-	printf("Switch to drawable 0x%x\n", drawable);
-#endif /* DEBUG_FONTSEL */
+	DEBUG(("Switch to drawable 0x%x\n", drawable));
 	fontPtr->ftDraw = XftDrawCreate(display, drawable,
 		DefaultVisual(display, fontPtr->screen),
 		DefaultColormap(display, fontPtr->screen));
     } else {
 	Tk_ErrorHandler handler =
@@ -1197,13 +1203,11 @@
     XftGlyphFontSpec specs[NUM_SPEC];
     XGlyphInfo metrics;
     double sinA = sin(angle * PI/180.0), cosA = cos(angle * PI/180.0);
 
     if (fontPtr->ftDraw == 0) {
-#ifdef DEBUG_FONTSEL
-	printf("Switch to drawable 0x%lx\n", drawable);
-#endif /* DEBUG_FONTSEL */
+	DEBUG(("Switch to drawable 0x%lx\n", drawable));
 	fontPtr->ftDraw = XftDrawCreate(display, drawable,
 		DefaultVisual(display, fontPtr->screen),
 		DefaultColormap(display, fontPtr->screen));
     } else {
 	Tk_ErrorHandler handler =