LibGUI: Set TextEditor to unmodified after saving size=0 files

This fixes #7946

Previously, TextEditor::write_to_file() would not mark its document
as unmodified if the file size was 0. This caused a desync in the
Text Editor app between the window's is_modified state and the
TextEditor's. It's already noted in the comments of the app's
save action code that propagating the modified state automatically
would be good, and it would solve issues like this, but I'm not yet
familiar enough with the code to try a change like that.

1 files changed, 16 insertions, 15 deletions

diff --git a/Userland/Libraries/LibGUI/TextEditor.cpp b/Userland/Libraries/LibGUI/TextEditor.cpp
index 3880d28cfe..3b2ca5277b 100644
--- a/Userland/Libraries/LibGUI/TextEditor.cpp
+++ b/Userland/Libraries/LibGUI/TextEditor.cpp
@@ -1170,25 +1170,26 @@ bool TextEditor::write_to_file(const String& path)
         return false;
     }
 
-    if (file_size == 0)
-        return true;
-
-    for (size_t i = 0; i < line_count(); ++i) {
-        auto& line = this->line(i);
-        if (line.length()) {
-            auto line_as_utf8 = line.to_utf8();
-            ssize_t nwritten = write(fd, line_as_utf8.characters(), line_as_utf8.length());
-            if (nwritten < 0) {
+    if (file_size == 0) {
+        // A size 0 file doesn't need a data copy.
+    } else {
+        for (size_t i = 0; i < line_count(); ++i) {
+            auto& line = this->line(i);
+            if (line.length()) {
+                auto line_as_utf8 = line.to_utf8();
+                ssize_t nwritten = write(fd, line_as_utf8.characters(), line_as_utf8.length());
+                if (nwritten < 0) {
+                    perror("write");
+                    return false;
+                }
+            }
+            char ch = '\n';
+            ssize_t nwritten = write(fd, &ch, 1);
+            if (nwritten != 1) {
                 perror("write");
                 return false;
             }
         }
-        char ch = '\n';
-        ssize_t nwritten = write(fd, &ch, 1);
-        if (nwritten != 1) {
-            perror("write");
-            return false;
-        }
     }
     document().set_unmodified();
     return true;