GroupNumericInput: it used to be that typing "0.0" would render "0." and then if

you typed "1", it would change to "0.01" which was pretty ugly.

This now works as expected

Author: migueldeicaza

Sources/SwiftTerm/Terminal.swift

@@ -1239,21 +1239,29 @@ open class Terminal {
                         let lastx = last.x >= cols ? cols-1 : last.x
                         var cd = existingLine [lastx]
 
-                        // Attemp the combination
+                        // Attempt the combination
                         let newStr = String ([cd.getCharacter (), ch])
 
                         // If the resulting string is 1 grapheme cluster, then it combined properly
                         if newStr.count == 1 {
+                            let oldSize = cd.width
+                            let newSize: Int8
+
                             if let newCh = newStr.first {
                                 switch firstScalar.value {
                                     // This is the "This should use color modifier" on the previous item
                                     // and we are going to take this to mean two columns
                                     // See https://github.com/migueldeicaza/SwiftTerm/pull/412
                                 case 0xFE0F:
                                     cd.setValue(char: newCh, size: 2)
-
+                                    if oldSize != 2 {
+                                        buffer.x += 1
+                                    }
                                 default:
                                     cd.setValue(char: newCh, size: Int32 (cd.width))
+                                    if cd.width != oldSize {
+                                        buffer.x += 1
+                                    }
                                 }
                                 existingLine [lastx] = cd
                                 updateRange (last.y)

Tests/SwiftTermTests/UnicodeTests.swift

@@ -61,21 +61,57 @@ final class SwiftTermUnicode: XCTestCase {
         XCTAssertEqual(char2_0?.width, 1)
     }
 
+    func testCombinedPositioning() {
+        let h = HeadlessTerminal (queue: SwiftTermTests.queue) { exitCode in }
+        let t = h.terminal!
+
+        // Baseline, we know that "\u{1100}" will always use 2-columns
+        // This inserts a simple 2-column value, and then a 1-column value
+        t.feed (text: "\u{1100}x\n\r")
+        let char0_0 = t.getCharacter (col: 0, row: 0)
+        let char1_0 = t.getCharacter (col: 1, row: 0)
+        let char2_0 = t.getCharacter (col: 2, row: 0)
+        XCTAssertEqual(char0_0, "\u{1100}")
+        XCTAssertEqual(char1_0, "\u{0}")
+        XCTAssertEqual(char2_0, "x")
+
+        // Here we insert a value that upgrades from 1-column to 2-column when we see the
+        // \u{fe0f}, so we need to make sure that the character after that has its position updated.
+        t.feed (text: "\u{026e9}\u{0fe0f}x")
+        let char0_1 = t.getCharacter (col: 0, row: 1)
+        let char1_1 = t.getCharacter (col: 1, row: 1)
+        let char2_1 = t.getCharacter (col: 2, row: 1)
+        print("Got \(char0_1) \(char1_1) \(char2_1)")
+        XCTAssertEqual(char0_1, "\u{026e9}\u{0fe0f}")
+        XCTAssertEqual(char1_1, "\u{0}")
+        XCTAssertEqual(char2_1, "x")
+
+    }
+
     func testEmoji ()
     {
         let h = HeadlessTerminal (queue: SwiftTermTests.queue) { exitCode in }
         let t = h.terminal!
 
         // This sends emoji with skin tone modifiers
         // The base emoji and skin tone modifier should combine into a single character
-        t.feed (text: "👦🏻\r\n👦🏿\r\n")
+        t.feed (text: "👦🏻x\r\n👦🏿x\r\n")
 
         let char0_0 = t.getCharacter (col:0, row: 0)
+        let char1_0 = t.getCharacter (col:1, row: 0)
+        let char2_0 = t.getCharacter (col:2, row: 0)
+
         let char0_1 = t.getCharacter (col:0, row: 1)
+        let char1_1 = t.getCharacter (col:1, row: 1)
+        let char2_1 = t.getCharacter (col:2, row: 1)
 
         // Emoji with skin tone modifiers should be combined into a single grapheme cluster
         XCTAssertEqual(char0_0, "👦🏻")
+        XCTAssertEqual(char1_0, "\u{0}")
+        XCTAssertEqual(char2_0, "x")
         XCTAssertEqual(char0_1, "👦🏿")
+        XCTAssertEqual(char1_1, "\u{0}")
+        XCTAssertEqual(char2_1, "x")
     }
 
     func testEmojiWithModifierBase ()