[PATCH] diesys calls die and also reports strerror(errno)

[Alexander Potashev <aspotashev@gmail.com>]

Signed-off-by: Alexander Potashev <aspotashev@gmail.com>
---
Firstly I was going to write a 'adapt_to_fmt' function which would
double all inclusions of '%', and then use it for strerror(err) and
make printf-like functions happy (actually 'die_routine').

BUT, Have you ever seen an error description containing '%'? I haven't.
So, handling the case of '%'s is not worth injecting several dump lines
into the sources of the Beatiful Content Tracker.



 git-compat-util.h |    1 +
 usage.c           |   18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/git-compat-util.h b/git-compat-util.h
index f25f7f1..cbfee60 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -162,6 +162,7 @@ extern char *gitbasename(char *);
 /* General helper functions */
 extern void usage(const char *err) NORETURN;
 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
+extern void diesys(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
diff --git a/usage.c b/usage.c
index 820d09f..e20f696 100644
--- a/usage.c
+++ b/usage.c
@@ -60,6 +60,24 @@ void die(const char *err, ...)
 	va_end(params);
 }
 
+void diesys(const char *err, ...)
+{
+	va_list params;
+	char *fullfmt;
+	const char *strerr;
+
+	va_start(params, err);
+
+	strerr = strerror(errno);
+	if (strchr(strerr, '%'))
+		strerr = "<error description contains '%%'>";
+	fullfmt = xmalloc(strlen(err) + strlen(strerr) + 3);
+	sprintf(fullfmt, "%s: %s", err, strerr);
+	die_routine(fullfmt, params);
+
+	va_end(params);
+}
+
 int error(const char *err, ...)
 {
 	va_list params;
-- 
1.6.2.3