Re: [PATCH 1/2] color: make it easier for non-config to parse color specs

["René Scharfe" <rene.scharfe@lsrfire.ath.cx>]

Jeff King schrieb:
> We have very featureful color-parsing routines which are
> used for color.diff.* and other options. Let's make it
> easier to use those routines from other parts of the code.
> 
> This patch adds a color_parse_mem() helper function which
> takes a length-bounded string instead of a NUL-terminated
> one. While the helper is only a few lines long, it is nice
> to abstract this out so that:
> 
>  - callers don't forget to free() the temporary buffer
> 
>  - right now, it is implemented in terms of color_parse().
>    But it would be more efficient to reverse this and
>    implement color_parse in terms of color_parse_mem.

Thusly?

diff --git a/color.c b/color.c
index fc0b72a..14eac93 100644
--- a/color.c
+++ b/color.c
@@ -41,6 +41,11 @@ static int parse_attr(const char *name, int len)
 
 void color_parse(const char *value, const char *var, char *dst)
 {
+	color_parse_mem(value, strlen(value), var, dst);
+}
+
+void color_parse_mem(const char *value, int len, const char *var, char *dst)
+{
 	const char *ptr = value;
 	int attr = -1;
 	int fg = -2;
@@ -52,18 +57,22 @@ void color_parse(const char *value, const char *var, char *dst)
 	}
 
 	/* [fg [bg]] [attr] */
-	while (*ptr) {
+	while (len > 0) {
 		const char *word = ptr;
-		int val, len = 0;
+		int val, wordlen = 0;
 
-		while (word[len] && !isspace(word[len]))
-			len++;
+		while (len > 0 && !isspace(word[wordlen])) {
+			wordlen++;
+			len--;
+		}
 
-		ptr = word + len;
-		while (*ptr && isspace(*ptr))
+		ptr = word + wordlen;
+		while (len > 0 && isspace(*ptr)) {
 			ptr++;
+			len--;
+		}
 
-		val = parse_color(word, len);
+		val = parse_color(word, wordlen);
 		if (val >= -1) {
 			if (fg == -2) {
 				fg = val;
@@ -75,7 +84,7 @@ void color_parse(const char *value, const char *var, char *dst)
 			}
 			goto bad;
 		}
-		val = parse_attr(word, len);
+		val = parse_attr(word, wordlen);
 		if (val < 0 || attr != -1)
 			goto bad;
 		attr = val;