Wild stab at fixing overlapping renames ...

Taking a list of files in an otherwise empty directory like:
    01.txt
    02.txt
    03.txt

And making it into:
    02.txt
    03.txt
    04.txt

Will naively create these operations:
    mv 01.txt 02.txt
    mv 02.txt 03.txt
    mv 03.txt 04.txt

And since they are performed in order, the final directory state will
contain a single file, 04.txt, which will be the 01.txt from the
original list.  This is not the most likely intention.  Performing the
operations in the reverse order would result in the most likely, desired
outcome.  However, more complext situations could arise where files are
renamed in an arbitrary order that would not be handled in a naive pass
either forward or backward.  The solution here is a loop that tries
until there are 2 passes across the list of operations in which no files
are renamed.

Ideally this would be tested for ahead of time instead of leaving the
directory in an intermediate state.  But that would exceed "wild stab"
level of implementation.  :)

vimv

@@ -28,16 +28,36 @@ if (( ${#src[@]} != ${#dest[@]} )); then
     exit 1
 fi
 
-declare -i count=0
+declare -i desired_renames=0
 for ((i=0;i<${#src[@]};++i)); do
     if [ "${src[i]}" != "${dest[i]}" ]; then
-        mkdir -p "$(dirname "${dest[i]}")"
-        if git ls-files --error-unmatch "${src[i]}" > /dev/null 2>&1; then
-            git mv "${src[i]}" "${dest[i]}"
-        else
-            mv "${src[i]}" "${dest[i]}"
+        ((++desired_renames))
+    fi
+done
+
+declare -i fruitless_attempts=0
+declare -i old_count=0
+declare -i count=0
+while [ "$fruitless_attempts" -lt 2 ] && [ "$count" != "$desired_renames" ]; do
+    for ((i=0;i<${#src[@]};++i)); do
+        if [ "${src[i]}" != "${dest[i]}" ]; then
+            if [ ! -e "${dest[i]}" ]; then
+                mkdir -p "$(dirname "${dest[i]}")"
+                if git ls-files --error-unmatch "${src[i]}" > /dev/null 2>&1; then
+                    git mv "${src[i]}" "${dest[i]}"
+                else
+                    mv -n "${src[i]}" "${dest[i]}"
+                fi
+                ((++count))
+            else
+                continue
+            fi
         fi
-        ((++count))
+    done
+    if [ "$count" != "$old_count" ]; then
+        ((old_count=count))
+    else
+        ((++fruitless_attempts))
     fi
 done