Added p4merge as mergetool in git config (only if OS is windows).

dot_gitconfig.tmpl

@@ -14,17 +14,17 @@
     ll = log --pretty=format:"%C(yellow)%h%Cred%d\\ %Creset%s%Cblue\\ [%cn]%Creset%Cgreen\\ (%cd)" --decorate --numstat --date=relative
     ld = log --pretty=format:"%C(yellow)%h\\ %C(green)%ad%Cred%d\\ %Creset%s%Cblue\\ [%cn]" --decorate --date=short --graph
     ls = log --pretty=format:"%C(green)%h\\ %C(yellow)[%ad]%Cred%d\\ %Creset%s%Cblue\\ [%cn]" --decorate --date=relative
-    
+
     # Short summary of commiters
     summary = shortlog --summary --numbered --email
-    
+
     # https://stackoverflow.com/questions/5188320/how-can-i-get-a-list-of-git-branches-ordered-by-most-recent-commit
     # list remote branches ordered by date
-    rr = for-each-ref --sort=-committerdate refs/remotes/ --count=20 --format='%(HEAD) %(color:yellow)%(refname:short)%(color:reset) - %(color:red)%(objectname:short)%(color:reset) - %(contents:subject) - %(authorname) (%(color:green)%(committerdate:relative)%(color:reset))' 
+    rr = for-each-ref --sort=-committerdate refs/remotes/ --count=20 --format='%(HEAD) %(color:yellow)%(refname:short)%(color:reset) - %(color:red)%(objectname:short)%(color:reset) - %(contents:subject) - %(authorname) (%(color:green)%(committerdate:relative)%(color:reset))'
 
     # show tracked files
     ls-tracked = ls-tree -r --name-only HEAD
-	
+
     # show number of commits per author
     # https://stackoverflow.com/questions/9839083/git-number-of-commits-per-author-on-all-branches
     stats = shortlog -s -n --all --no-merges
@@ -45,26 +45,44 @@
     ss = status -s --branch -uno
     co = checkout
     pr = remote prune origin
-    
+
     # from pixelbeat
     brdate = for-each-ref --sort=-committerdate --format='%(committerdate:iso8601) %(refname:short)' refs/heads/
-	st = stash list --date=local
-	alias = ! git config --get-regexp ^alias\\. | sed -e s/^alias\\.// -e s/\\ /\\ =\\ /
-	d = diff -w
-	dc = diff -w --cached
+    st = stash list --date=local
+    alias = ! git config --get-regexp ^alias\\. | sed -e s/^alias\\.// -e s/\\ /\\ =\\ /
+    d = diff -w
+    dc = diff -w --cached
 
     # from https://www.toptal.com/developers/gitignore
     # create .gitignore templates based on operationg systems, IDE, languages etc.
     ignore = "!gi() { curl -sL https://www.toptal.com/developers/gitignore/api/$@ ;}; gi"
-      
+
 [core]
-	editor = vim
+    editor = vim
 
 [push]
     # default = matching
     default = simple # safer option, push only current branch
+[pull]
+    ff = only
+
+{{ if eq .chezmoi.os "windows" -}}
 [merge]
     tool = p4merge
-	ff = false
-[pull]
-	ff = only
+    ff = false
+
+[mergetool "p4merge"]
+    path = "C:\\Program Files\\Perforce\\p4merge.exe"
+    cmd = p4merge $BASE $LOCAL $REMOTE $MERGED
+    keepBackup = false
+
+[difftool "p4merge"]
+    external = p4merge $LOCAL $REMOTE
+
+[difftool "winmerge"]
+    cmd = "'c:/PortableApps/PortableApps/WinMergePortable/App/WinMerge/WinMergeU'" -e "$LOCAL" "$REMOTE"
+
+{{ end -}}
+
+[http]
+    # proxy = http://host:port