1 files changed, 65 insertions, 14 deletions

diff --git a/usage.c b/usage.c
index b6aea45280..ed146453ca 100644
--- a/usage.c
+++ b/usage.c
@@ -4,69 +4,119 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "git-compat-util.h"
+#include "cache.h"
 
-static void report(const char *prefix, const char *err, va_list params)
+void vreportf(const char *prefix, const char *err, va_list params)
 {
-	char msg[1024];
+	char msg[4096];
 	vsnprintf(msg, sizeof(msg), err, params);
 	fprintf(stderr, "%s%s\n", prefix, msg);
 }
 
-static NORETURN void usage_builtin(const char *err)
+void vwritef(int fd, const char *prefix, const char *err, va_list params)
 {
-	fprintf(stderr, "usage: %s\n", err);
+	char msg[4096];
+	int len = vsnprintf(msg, sizeof(msg), err, params);
+	if (len > sizeof(msg))
+		len = sizeof(msg);
+
+	write_in_full(fd, prefix, strlen(prefix));
+	write_in_full(fd, msg, len);
+	write_in_full(fd, "\n", 1);
+}
+
+static NORETURN void usage_builtin(const char *err, va_list params)
+{
+	vreportf("usage: ", err, params);
 	exit(129);
 }
 
 static NORETURN void die_builtin(const char *err, va_list params)
 {
-	report("fatal: ", err, params);
+	vreportf("fatal: ", err, params);
 	exit(128);
 }
 
 static void error_builtin(const char *err, va_list params)
 {
-	report("error: ", err, params);
+	vreportf("error: ", err, params);
 }
 
 static void warn_builtin(const char *warn, va_list params)
 {
-	report("warning: ", warn, params);
+	vreportf("warning: ", warn, params);
+}
+
+static int die_is_recursing_builtin(void)
+{
+	static int dying;
+	return dying++;
 }
 
 /* If we are in a dlopen()ed .so write to a global variable would segfault
  * (ugh), so keep things static. */
-static void (*usage_routine)(const char *err) NORETURN = usage_builtin;
-static void (*die_routine)(const char *err, va_list params) NORETURN = die_builtin;
+static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
+static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
 static void (*error_routine)(const char *err, va_list params) = error_builtin;
 static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
+static int (*die_is_recursing)(void) = die_is_recursing_builtin;
 
-void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
+void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
 {
 	die_routine = routine;
 }
 
-void usage(const char *err)
+void set_error_routine(void (*routine)(const char *err, va_list params))
 {
-	usage_routine(err);
+	error_routine = routine;
 }
 
-void die(const char *err, ...)
+void set_die_is_recursing_routine(int (*routine)(void))
+{
+	die_is_recursing = routine;
+}
+
+void NORETURN usagef(const char *err, ...)
 {
 	va_list params;
 
 	va_start(params, err);
+	usage_routine(err, params);
+	va_end(params);
+}
+
+void NORETURN usage(const char *err)
+{
+	usagef("%s", err);
+}
+
+void NORETURN die(const char *err, ...)
+{
+	va_list params;
+
+	if (die_is_recursing()) {
+		fputs("fatal: recursion detected in die handler\n", stderr);
+		exit(128);
+	}
+
+	va_start(params, err);
 	die_routine(err, params);
 	va_end(params);
 }
 
-void die_errno(const char *fmt, ...)
+void NORETURN die_errno(const char *fmt, ...)
 {
 	va_list params;
 	char fmt_with_err[1024];
 	char str_error[256], *err;
 	int i, j;
 
+	if (die_is_recursing()) {
+		fputs("fatal: recursion detected in die_errno handler\n",
+			stderr);
+		exit(128);
+	}
+
 	err = strerror(errno);
 	for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 		if ((str_error[j++] = err[i++]) != '%')
@@ -88,6 +138,7 @@ void die_errno(const char *fmt, ...)
 	va_end(params);
 }
 
+#undef error
 int error(const char *err, ...)
 {
 	va_list params;