v3-0001-command-line-colorization-on-windows.patch

diff --git a/src/common/logging.c b/src/common/logging.c
index c78ae79..8c0377f 100644
--- a/src/common/logging.c
+++ b/src/common/logging.c
@@ -32,6 +32,60 @@ static const char *sgr_locus = NULL;
 #define ANSI_ESCAPE_FMT "\x1b[%sm"
 #define ANSI_ESCAPE_RESET "\x1b[0m"
 
+#define str_starts_with(str, substr) (strncmp(str, substr, strlen(substr)) == 0)
+#define str_ends_with(str, substr) (strcmp(str + strlen(str) - strlen(substr), substr) == 0)
+#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
+#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
+#endif
+
+static bool
+terminal_supports_color(void)
+{
+#ifndef WIN32
+	const char *term_env = getenv("TERM");
+
+	if (!term_env)
+		return false;
+	else if (strcmp(term_env, "ansi") == 0)
+		return true;
+	else if (strcmp(term_env, "cygwin") == 0)
+		return true;
+	else if (strcmp(term_env, "linux") == 0)
+		return true;
+	else if (str_starts_with(term_env, "rxvt"))
+		return true;
+	else if (str_starts_with(term_env, "screen"))
+		return true;
+	else if (str_starts_with(term_env, "xterm"))
+		return true;
+	else if (str_starts_with(term_env, "vt100"))
+		return true;
+	else if (str_ends_with(term_env, "color"))
+		return true;
+	else
+		return false;
+#else
+/*
+ * Windows supports color on console's VT100 mode.
+ * It is disabled by default, so it must be enabled to use color outpout.
+ */
+	/* Check stderr */
+	HANDLE hOut = GetStdHandle(STD_ERROR_HANDLE);
+	DWORD dwMode = 0;
+
+	if (hOut == INVALID_HANDLE_VALUE)
+		return false;
+	if (!GetConsoleMode(hOut, &dwMode))
+		return false;
+	if (dwMode & ENABLE_VIRTUAL_TERMINAL_PROCESSING)
+		return true;
+	dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+	if (!SetConsoleMode(hOut, dwMode))
+		return false;
+	return true;
+#endif
+}
+
 /*
  * This should be called before any output happens.
  */
@@ -40,6 +94,8 @@ pg_logging_init(const char *argv0)
 {
 	const char *pg_color_env = getenv("PG_COLOR");
 	bool		log_color = false;
+	bool		color_terminal = isatty(fileno(stderr)) &&
+								 terminal_supports_color();
 
 	/* usually the default, but not on Windows */
 	setvbuf(stderr, NULL, _IONBF, 0);
@@ -50,7 +106,7 @@ pg_logging_init(const char *argv0)
 	if (pg_color_env)
 	{
 		if (strcmp(pg_color_env, "always") == 0 ||
-			(strcmp(pg_color_env, "auto") == 0 && isatty(fileno(stderr))))
+			(strcmp(pg_color_env, "auto") == 0 && color_terminal))
 			log_color = true;
 	}