[tarantool-patches] [PATCH] sql: fix bug with BLOB TRIM() when X'00' in char set

[Roman Khabibov <roman.habibov@tarantool.org>]

The reason for the bug was that X'00' is a terminal symbol. If the char set
contained X'00', all other characters after its (inculding itself) are then
ignored.

Closes #3543

Branch: https://github.com/tarantool/tarantool/tree/romankhabibov/gh-3543-trim-terminal
Issue: https://github.com/tarantool/tarantool/issues/3543
---
 src/box/sql/func.c         |  18 +++++-
 test/sql-tap/func.test.lua | 126 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 140 insertions(+), 4 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 9667aead5..5beba7bd2 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -1224,8 +1224,16 @@ trimFunc(sqlite3_context * context, int argc, sqlite3_value ** argv)
 		return;
 	} else {
 		const unsigned char *z;
-		for (z = zCharSet, nChar = 0; *z; nChar++) {
+		int sizeInChar = sqlite3_value_bytes(argv[1]);
+		int length = 0;
+		z = zCharSet;
+		nChar = 0;
+		const unsigned char *zStepBack;
+		while(sizeInChar - length) {
+			zStepBack = z;
 			SQLITE_SKIP_UTF8(z);
+			length += z - zStepBack;
+			nChar++;
 		}
 		if (nChar > 0) {
 			azChar =
@@ -1235,10 +1243,16 @@ trimFunc(sqlite3_context * context, int argc, sqlite3_value ** argv)
 				return;
 			}
 			aLen = (unsigned char *)&azChar[nChar];
-			for (z = zCharSet, nChar = 0; *z; nChar++) {
+			z = zCharSet;
+			nChar = 0;
+			length = 0;
+			while(sizeInChar - length) {
 				azChar[nChar] = (unsigned char *)z;
+				zStepBack = z;
 				SQLITE_SKIP_UTF8(z);
+				length += z - zStepBack;
 				aLen[nChar] = (u8) (z - azChar[nChar]);
+				nChar++;
 			}
 		}
 	}
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 393212968..b7b8e7c4c 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 test = require("sqltester")
-test:plan(14535)
+test:plan(14547)
 
 --!./tcltestrunner.lua
 -- 2001 September 15
@@ -2100,11 +2100,133 @@ test:do_execsql_test(
         -- </func-22.22>
     })
 
+-- gh-3543 Check trimming of binary string when X'00' in trimming char set.
+
+test:do_execsql_test(
+    "func-22.23",
+    [[
+        SELECT TRIM(X'004100', X'00');
+    ]], {
+        -- <func-22.23>
+        "A"
+        -- </func-22.23>
+    })
+
+test:do_execsql_test(
+    "func-22.24",
+    [[
+        SELECT TRIM(X'004100', X'0000');
+    ]], {
+        -- <func-22.24>
+        "A"
+        -- </func-22.24>
+    })
+
+test:do_execsql_test(
+    "func-22.25",
+    [[
+        SELECT TRIM(X'004100', X'0042');
+    ]], {
+        -- <func-22.25>
+        "A"
+        -- </func-22.25>
+    })
+
+test:do_execsql_test(
+    "func-22.26",
+    [[
+        SELECT TRIM(X'00004100420000', X'00');
+    ]], {
+        -- <func-22.26>
+        "A\0B"
+        -- </func-22.26>
+    })
+
+test:do_execsql_test(
+    "func-22.27",
+    [[
+        SELECT LTRIM(X'004100', X'00');
+    ]], {
+        -- <func-22.27>
+        "A\0"
+        -- </func-22.27>
+    })
+
+test:do_execsql_test(
+    "func-22.28",
+    [[
+        SELECT LTRIM(X'004100', X'0000');
+    ]], {
+        -- <func-22.28>
+        "A\0"
+        -- </func-22.28>
+    })
+
+test:do_execsql_test(
+    "func-22.29",
+    [[
+        SELECT LTRIM(X'004100', X'0042');
+    ]], {
+        -- <func-22.29>
+        "A\0"
+        -- </func-22.29>
+    })
+
+test:do_execsql_test(
+    "func-22.30",
+    [[
+        SELECT LTRIM(X'00004100420000', X'00');
+    ]], {
+        -- <func-22.30>
+        "A\0B\0\0"
+        -- </func-22.30>
+    })
+
+test:do_execsql_test(
+    "func-22.31",
+    [[
+        SELECT RTRIM(X'004100', X'00');
+    ]], {
+        -- <func-22.31>
+        "\0A"
+        -- </func-22.31>
+    })
+
+test:do_execsql_test(
+    "func-22.32",
+    [[
+        SELECT RTRIM(X'004100', X'0000');
+    ]], {
+        -- <func-22.32>
+        "\0A"
+        -- </func-22.32>
+    })
+
+test:do_execsql_test(
+    "func-22.33",
+    [[
+        SELECT RTRIM(X'004100', X'0042');
+    ]], {
+        -- <func-22.33>
+        "\0A"
+        -- </func-22.33>
+    })
+
+test:do_execsql_test(
+    "func-22.34",
+    [[
+        SELECT RTRIM(X'00004100420000', X'00');
+    ]], {
+        -- <func-22.34>
+        "\0\0A\0B"
+        -- </func-22.34>
+    })
+
 -- This is to test the deprecated sqlite3_aggregate_count() API.
 --
 --test:do_test(
 --    "func-23.1",
---    function()
+--    function()S
 --        sqlite3_create_aggregate("db")
 --        return test:execsql([[
 --            SELECT legacy_count() FROM t6;
-- 
2.17.1