[git commit master] unexpand: fix "a b"\n" input case

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=968951fd0ced7d0d4b81c0ee4466eada93ae4128
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

Signed-off-by: Tomas Heinrich <heinrich.tomas at gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 coreutils/expand.c       |   17 ++++++++++-------
 testsuite/unexpand.tests |    3 +++
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/coreutils/expand.c b/coreutils/expand.c
index 60ac9f5..cfb1e25 100644
--- a/coreutils/expand.c
+++ b/coreutils/expand.c
@@ -81,12 +81,13 @@ static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
 
 		while (*ptr) {
 			unsigned n;
-			unsigned len;
+			unsigned len = 0;
 
 			while (*ptr == ' ') {
-				column++;
 				ptr++;
+				len++;
 			}
+			column += len;
 			if (*ptr == '\t') {
 				column += tab_size - (column % tab_size);
 				ptr++;
@@ -94,16 +95,18 @@ static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
 			}
 
 			n = column / tab_size;
-			column = column % tab_size;
-			while (n--)
-				putchar('\t');
+			if (n) {
+				len = column = column % tab_size;
+				while (n--)
+					putchar('\t');
+			}
 
 			if ((opt & OPT_INITIAL) && ptr != line) {
-				printf("%*s%s", column, "", ptr);
+				printf("%*s%s", len, "", ptr);
 				break;
 			}
 			n = strcspn(ptr, "\t ");
-			printf("%*s%.*s", column, "", n, ptr);
+			printf("%*s%.*s", len, "", n, ptr);
 # if ENABLE_FEATURE_ASSUME_UNICODE
 			{
 				char c;
diff --git a/testsuite/unexpand.tests b/testsuite/unexpand.tests
index 5c2a29b..1af2fdc 100755
--- a/testsuite/unexpand.tests
+++ b/testsuite/unexpand.tests
@@ -27,6 +27,9 @@ testing "unexpand case 6" "unexpand" \
 testing "unexpand case 7" "unexpand" \
 	"123\t 45678\n" "" "123 \t 45678\n" \
 
+testing "unexpand case 8" "unexpand" \
+	"a b\n" "" "a b\n" \
+
 testing "unexpand with unicode characher 0x394" "unexpand" \
 	"1ΔΔΔ5\t99999\n" "" "1ΔΔΔ5   99999\n" \
 
-- 
1.6.3.3