split_cmdline: Allow caller to access error string

This allows the caller to add its own error message to that returned
by split_cmdline.  Thus error output following a failed split_cmdline
can be of the form

fatal: Bad alias.test string: cmdline ends with \

rather than

error: cmdline ends with \
fatal: Bad alias.test string

Signed-off-by: Greg Brockman <gdb@mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/alias.c b/alias.c
index 372b7d8093..eb9f08b912 100644
--- a/alias.c
+++ b/alias.c
@@ -22,6 +22,13 @@ char *alias_lookup(const char *alias)
 	return alias_val;
 }
 
+#define SPLIT_CMDLINE_BAD_ENDING 1
+#define SPLIT_CMDLINE_UNCLOSED_QUOTE 2
+static const char *split_cmdline_errors[] = {
+	"cmdline ends with \\",
+	"unclosed quote"
+};
+
 int split_cmdline(char *cmdline, const char ***argv)
 {
 	int src, dst, count = 0, size = 16;
@@ -53,7 +60,7 @@ int split_cmdline(char *cmdline, const char ***argv)
 				if (!c) {
 					free(*argv);
 					*argv = NULL;
-					return error("cmdline ends with \\");
+					return -SPLIT_CMDLINE_BAD_ENDING;
 				}
 			}
 			cmdline[dst++] = c;
@@ -66,7 +73,7 @@ int split_cmdline(char *cmdline, const char ***argv)
 	if (quoted) {
 		free(*argv);
 		*argv = NULL;
-		return error("unclosed quote");
+		return -SPLIT_CMDLINE_UNCLOSED_QUOTE;
 	}
 
 	ALLOC_GROW(*argv, count+1, size);
@@ -75,3 +82,6 @@ int split_cmdline(char *cmdline, const char ***argv)
 	return count;
 }
 
+const char *split_cmdline_strerror(int split_cmdline_errno) {
+	return split_cmdline_errors[-split_cmdline_errno-1];
+}