The fix for bug [8d073be8808beaa7b614b6d489e729dfb51ac114] only seems to have fixed the issue for the gdiff command. If editor contains spaces, executing it still fails.

<verbatim>
C:\Docs\Projects\01. Lean SDMC>fossil commit
c:/Program Files/Vim/vim73/gvim.exe "C:/<snipped>/ci-comment-5
260D688DBC8.txt"
'c:/Program' is not recognized as an internal or external command,
operable program or batch file.
c:\Docs\Bin\fossil.exe: editor aborted
</verbatim>

Diff below fixes this, but a better solution would probably be to extend the portable_system command to cover all uses of fossil_system

--- src/checkin.c
+++ src/checkin.c
@@ -442,11 +442,11 @@
 #if defined(_WIN32)
   blob_add_cr(&text);
 #endif
   blob_write_to_file(&text, zFile);
   if( zEditor ){
-    zCmd = mprintf("%s \"%s\"", zEditor, zFile);
+    zCmd = mprintf("\"%s\" \"%s\"", zEditor, zFile);
     printf("%s\n", zCmd);
     if( fossil_system(zCmd) ){
       fossil_panic("editor aborted");
     }
     blob_reset(&text);