[PATCH v2] display_options: print_size: Fix order overflow

[Pali Rohár]

Function print_size() round size to the nearst value with one decimal
fraction number. But in special cases also unit order may overflow.

For example value 1073689396 is printed as "1024 MiB" and value 1073741824
as "1 GiB".

Fix this issue by detecting order overflow and increasing unit order.
With this change also value 1073689396 is printed as "1 GiB".

Signed-off-by: Pali Rohár <pali at kernel.org>

---
Changes in v2:
* Add unit test case
---
 lib/display_options.c | 6 ++++++
 test/lib/test_print.c | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/lib/display_options.c b/lib/display_options.c
index 360b01bcf5ff..59ed4f61b741 100644
--- a/lib/display_options.c
+++ b/lib/display_options.c
@@ -126,6 +126,12 @@ void print_size(uint64_t size, const char *s)
 		if (m >= 10) {
 			m -= 10;
 			n += 1;
+
+			if (n == 1024 && i > 0) {
+				n = 1;
+				m = 0;
+				c = names[i - 1];
+			}
 		}
 	}
 
diff --git a/test/lib/test_print.c b/test/lib/test_print.c
index a60a5a51f126..79b67c779321 100644
--- a/test/lib/test_print.c
+++ b/test/lib/test_print.c
@@ -68,6 +68,9 @@ static int lib_test_print_size(struct unit_test_state *uts)
 	ut_assertok(test_print_size(uts, 7654321, "7.3 MiB;"));
 	ut_assertok(test_print_size(uts, 87654321, "83.6 MiB;"));
 	ut_assertok(test_print_size(uts, 987654321, "941.9 MiB;"));
+	ut_assertok(test_print_size(uts, 1073689395, "1023.9 MiB;"));
+	ut_assertok(test_print_size(uts, 1073689396, "1 GiB;"));
+	ut_assertok(test_print_size(uts, 1073741824, "1 GiB;"));
 	ut_assertok(test_print_size(uts, 1987654321, "1.9 GiB;"));
 	ut_assertok(test_print_size(uts, 54321987654321, "49.4 TiB;"));
 	return 0;
-- 
2.20.1