Documentation: Describe other situations where -z affects git diff

diff --git a/color.h b/color.h
index 18abeb7c7dd47794d4f5fea4049b5719f03383fe..bcb28cf10f2cbef11d9dba0e5a7f3f0515cbbd70 100644 (file)
--- a/color.h
+++ b/color.h
@@ -1,9 +1,26 @@
 #ifndef COLOR_H
 #define COLOR_H
 
-/* "\033[1;38;5;2xx;48;5;2xxm\0" is 23 bytes */
-#define COLOR_MAXLEN 24
+/*  2 + (2 * num_attrs) + 8 + 1 + 8 + 'm' + NUL */
+/* "\033[1;2;4;5;7;38;5;2xx;48;5;2xxm\0" */
+/*
+ * The maximum length of ANSI color sequence we would generate:
+ * - leading ESC '['            2
+ * - attr + ';'                 2 * 8 (e.g. "1;")
+ * - fg color + ';'             9 (e.g. "38;5;2xx;")
+ * - fg color + ';'             9 (e.g. "48;5;2xx;")
+ * - terminating 'm' NUL        2
+ *
+ * The above overcounts attr (we only use 5 not 8) and one semicolon
+ * but it is close enough.
+ */
+#define COLOR_MAXLEN 40
 
+/*
+ * IMPORTANT: Due to the way these color codes are emulated on Windows,
+ * write them only using printf(), fprintf(), and fputs(). In particular,
+ * do not use puts() or write().
+ */
 #define GIT_COLOR_NORMAL       ""
 #define GIT_COLOR_RESET                "\033[m"
 #define GIT_COLOR_BOLD         "\033[1m"
@@ -29,7 +46,9 @@ int git_color_default_config(const char *var, const char *value, void *cb);
 int git_config_colorbool(const char *var, const char *value, int stdout_is_tty);
 void color_parse(const char *value, const char *var, char *dst);
 void color_parse_mem(const char *value, int len, const char *var, char *dst);
+__attribute__((format (printf, 3, 4)))
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
+__attribute__((format (printf, 3, 4)))
 int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
 int color_fwrite_lines(FILE *fp, const char *color, size_t count, const char *buf);