unexpand: fix "a b"\n" input case

Signed-off-by: Tomas Heinrich <heinrich.tomas@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 13 insertions, 7 deletions

diff --git a/coreutils/expand.c b/coreutils/expand.c
index 60ac9f568..cfb1e25d9 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 5c2a29b5f..1af2fdc5f 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" \