[CONJ-850] MariaDbResultSetMetaData#getPrecision(int) returns wrong length for character data

Author: rusher

src/main/java/org/mariadb/jdbc/MariaDbParameterMetaData.java

@@ -108,7 +108,7 @@ public boolean isSigned(int param) throws SQLException {
 
   @Override
   public int getPrecision(int param) throws SQLException {
-    long length = getParameterInformation(param).getLength();
+    long length = getParameterInformation(param).getPrecision();
     return (length > Integer.MAX_VALUE) ? Integer.MAX_VALUE : (int) length;
   }
 

src/main/java/org/mariadb/jdbc/internal/com/read/resultset/ColumnDefinition.java

@@ -273,6 +273,18 @@ public long getPrecision() {
         } else {
           return length - ((decimals > 0) ? 1 : 0);
         }
+      case VARCHAR:
+      case JSON:
+      case ENUM:
+      case SET:
+      case VARSTRING:
+      case STRING:
+        int maxWidth = maxCharlen[charsetNumber & 0xff];
+        if (maxWidth == 0) {
+          return length;
+        }
+        return length / maxWidth;
+
       default:
         return length;
     }

src/test/java/org/mariadb/jdbc/DatabaseMetadataTest.java

@@ -140,6 +140,11 @@ public static void initClass() throws SQLException {
               + "t4 timestamp(6) DEFAULT '2000-01-01 00:00:00',"
               + "t5 time(0),"
               + "t6 time(6))");
+      stmt.execute(
+              "CREATE TABLE getStringPrecision("
+                      + "col1 CHAR(100) CHARSET utf8mb4, "
+                      + "col2 CHAR(100) CHARSET utf8,"
+                      + "col3 CHAR(100) CHARSET latin2)");
       stmt.execute(
           "CREATE TABLE getTimePrecision2("
               + "d date, "
@@ -203,6 +208,7 @@ public static void afterClass() throws SQLException {
       stmt.execute("drop table if exists fore_key1");
       stmt.execute("drop table if exists prim_key");
       stmt.execute("drop table if exists table_type_test");
+      stmt.execute("drop table if exists getStringPrecision");
     }
   }
 
@@ -1448,6 +1454,24 @@ public void getTimePrecision() throws SQLException {
     assertEquals(6, rsmd.getScale(7));
   }
 
+
+  @Test
+  public void getStringPrecision() throws SQLException {
+    Assume.assumeTrue(doPrecisionTest);
+    Statement stmt = sharedConnection.createStatement();
+    ResultSet rs = stmt.executeQuery("SELECT * FROM getStringPrecision");
+    ResultSetMetaData rsmd = rs.getMetaData();
+    // CHAR(100) CHARSET=utf8mb4
+    assertEquals(100, rsmd.getPrecision(1));
+    assertEquals(0, rsmd.getScale(1));
+    // CHAR(100) CHARSET=utf8
+    assertEquals(100, rsmd.getPrecision(2));
+    assertEquals(0, rsmd.getScale(2));
+    // CHAR(100) CHARSET=latin2
+    assertEquals(100, rsmd.getPrecision(3));
+    assertEquals(0, rsmd.getScale(3));
+  }
+
   @Test
   public void metaTimeResultSet() throws SQLException {
     Assume.assumeTrue(doPrecisionTest);