REPLACE: if any parameter is null, the result is null.

h2/src/docsrc/help/help.csv

@@ -2756,6 +2756,7 @@ REGEXP_REPLACE(inputString, regexString, replacementString)
 ","
 Replaces each substring that matches a regular expression.
 For details, see the Java String.replaceAll() method.
+If any parameter is null, the result is null.
 ","
 REGEXP_REPLACE('Hello    World', ' +', ' ')
 "
@@ -2773,6 +2774,7 @@ REPLACE(string, searchString [, replacementString])
 ","
 Replaces all occurrences of a search string in a text with another string.
 If no replacement is specified, the search string is removed from the original string.
+If any parameter is null, the result is null.
 ","
 REPLACE(NAME, ' ')
 "

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Queries with DISTINCT and ORDER BY will now use the index on ORDER BY if possible.
+<ul><li>H2 Console: the built-in commands are now documented.
+</li><li>REPLACE: if any parameter is null, the result is null.
+</li><li>Queries with DISTINCT and ORDER BY will now use the index on ORDER BY if possible.
     This is specially important for queries used inside IN(SELECT ...).
 </li><li>The new statement EXPLAIN ANALYZE executes the statement, 
     and displays the query plan with the actual row scan count for each table.

h2/src/main/org/h2/expression/Function.java

@@ -220,7 +220,7 @@ public class Function extends Expression implements FunctionCall {
         addFunction("OCTET_LENGTH", OCTET_LENGTH, 1, Value.LONG);
         addFunction("RAWTOHEX", RAWTOHEX, 1, Value.STRING);
         addFunction("REPEAT", REPEAT, 2, Value.STRING);
-        addFunctionWithNull("REPLACE", REPLACE, VAR_ARGS, Value.STRING);
+        addFunction("REPLACE", REPLACE, VAR_ARGS, Value.STRING);
         addFunction("RIGHT", RIGHT, 2, Value.STRING);
         addFunction("RTRIM", RTRIM, VAR_ARGS, Value.STRING);
         addFunction("SOUNDEX", SOUNDEX, 1, Value.STRING);
@@ -945,9 +945,9 @@ public class Function extends Expression implements FunctionCall {
             break;
         }
         case REPLACE: {
-            String s0 = v0 == ValueNull.INSTANCE ? "" : v0.getString();
-            String s1 = v1 == ValueNull.INSTANCE ? "" : v1.getString();
-            String s2 = (v2 == null || v2 == ValueNull.INSTANCE) ? "" : v2.getString();
+            String s0 = v0.getString();
+            String s1 = v1.getString();
+            String s2 = (v2 == null) ? "" : v2.getString();
             result = ValueString.get(replace(s0, s1, s2));
             break;
         }
@@ -1313,7 +1313,10 @@ public class Function extends Expression implements FunctionCall {
     }
 
     private static String replace(String s, String replace, String with) {
-        if (replace == null || replace.length() == 0) {
+        if (s == null || replace == null || with == null) {
+            return null;
+        }
+        if (replace.length() == 0) {
             // avoid out of memory
             return s;
         }

h2/src/test/org/h2/test/test-1.2.txt

@@ -8825,9 +8825,9 @@ select repeat(null, null) en, repeat('Ho', 2) abcehoho , repeat('abc', 0) ee fro
 > rows: 1
 
 select replace(null, null) en, replace(null, null, null) en1 from test;
-> EN EN1
-> -- ---
->
+> EN   EN1
+> ---- ----
+> null null
 > rows: 1
 
 select replace('abchihihi', 'i', 'o') abcehohoho, replace('that is tom', 'i') abcethstom from test;