>From ba267757d0dd8bcae9bfa9afd789700645eee9b2 Mon Sep 17 00:00:00 2001
From: Brand Huntsman <address@hidden>
Date: Mon, 29 Jan 2018 16:51:47 -0700
Subject: [PATCH 1/2] get number of terminal colors

Signed-off-by: Brand Huntsman <address@hidden>
---
 src/color.c  | 34 ++++++++++++++++++++++++++++++++++
 src/global.c |  2 ++
 src/nano.c   |  4 ++++
 src/proto.h  |  2 ++
 4 files changed, 42 insertions(+)

diff --git a/src/color.c b/src/color.c
index 329ed41d..108af9f8 100644
--- a/src/color.c
+++ b/src/color.c
@@ -27,6 +27,7 @@
 #endif
 #include <string.h>
 #include <unistd.h>
+#include <term.h>
 
 #ifdef ENABLE_COLOR
 
@@ -431,4 +432,37 @@ void precalc_multicolorinfo(void)
 	}
 }
 
+#if defined(NCURSES_VERSION_MAJOR) && (NCURSES_VERSION_MAJOR >= 6)
+#define HAS_EXTENDED_COLORS 1
+#else
+#define HAS_EXTENDED_COLORS 0
+#endif
+
+/* Get number of colors supported by terminal and initialize lookup tables. */
+void extended_color_init(void)
+{
+	if (!has_colors())
+		nr_term_colors = 0;
+
+	if (tgetent(NULL, getenv("TERM")) != 1) {
+		nr_term_colors = 0;
+		return;
+	}
+	nr_term_colors = tgetnum("Co");
+
+	if (nr_term_colors > 16 && !HAS_EXTENDED_COLORS) {
+		/* No support for extended colors. */
+		nr_term_colors = 16;
+	} else if (nr_term_colors > 256) {
+		nr_term_colors = 256;
+	} else if (nr_term_colors > 16) {
+		if (nr_term_colors != 256 && nr_term_colors != 88)
+			nr_term_colors = 16;
+	} else if (nr_term_colors > 8) {
+		if (nr_term_colors != 16)
+			nr_term_colors = 8;
+	} else if (nr_term_colors != 8)
+		nr_term_colors = 0;
+}
+
 #endif /* ENABLE_COLOR */
diff --git a/src/global.c b/src/global.c
index fadd6fdc..afe565d2 100644
--- a/src/global.c
+++ b/src/global.c
@@ -183,6 +183,8 @@ char *syntaxstr = NULL;
 		/* The color syntax name specified on the command line. */
 bool have_palette = FALSE;
 		/* Whether the colors for the current syntax have been initialized. */
+int nr_term_colors = 0;
+		/* Number of colors supported by terminal. */
 #endif
 
 bool refresh_needed = FALSE;
diff --git a/src/nano.c b/src/nano.c
index 12543dd4..ab92726f 100644
--- a/src/nano.c
+++ b/src/nano.c
@@ -1992,6 +1992,10 @@ int main(int argc, char **argv)
 	console = (getenv("DISPLAY") == NULL);
 #endif
 
+#ifdef ENABLE_COLOR
+	extended_color_init();
+#endif
+
 	/* Back up the terminal settings so that they can be restored. */
 	tcgetattr(0, &oldterm);
 
diff --git a/src/proto.h b/src/proto.h
index a7d90689..c575a7a1 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -144,6 +144,7 @@ extern char *alt_speller;
 extern syntaxtype *syntaxes;
 extern char *syntaxstr;
 extern bool have_palette;
+extern int nr_term_colors;
 #endif
 
 extern bool refresh_needed;
@@ -248,6 +249,7 @@ void color_update(void);
 void check_the_multis(filestruct *line);
 void alloc_multidata_if_needed(filestruct *fileptr);
 void precalc_multicolorinfo(void);
+void extended_color_init(void);
 #endif
 
 /* Most functions in cut.c. */
-- 
2.13.6