Post-update hook should not run in case of an error

plug.vim

@@ -646,7 +646,7 @@ function! s:do(pull, force, todo)
     endif
     let installed = has_key(s:update.new, name)
     let updated = installed ? 0 :
-      \ (a:pull && !empty(s:system_chomp('git log --pretty=format:"%h" "HEAD...HEAD@{1}"', spec.dir)))
+      \ (a:pull && index(s:update.errors, name) < 0 && !empty(s:system_chomp('git log --pretty=format:"%h" "HEAD...HEAD@{1}"', spec.dir)))
     if a:force || installed || updated
       execute 'cd' s:esc(spec.dir)
       call append(3, '- Post-update hook for '. name .' ... ')

test/workflow.vader

@@ -756,6 +756,28 @@ Execute (Using Funcref):
   Assert filereadable(g:plugs['vim-pseudocl'].dir.'/vim-pseudoclunchanged13'),
     \ 'vim-pseudocl/vim-pseudoclunchanged13 should exist'
 
+Execute (Should not run when failed to update):
+  call plug#begin()
+  Plug 'junegunn/vim-easy-align', { 'do': 'touch failed'     }
+  Plug 'junegunn/vim-pseudocl',   { 'do': 'touch not-failed' }
+  call plug#end()
+
+  " Invalid remote URL
+  call system(printf('cd %s && git remote set-url origin xxx', g:plugs['vim-easy-align'].dir))
+
+  " New commits on remote
+  call system('cd /tmp/junegunn/vim-easy-align && git commit --allow-empty -m "update"')
+  call system('cd /tmp/junegunn/vim-pseudocl && git commit --allow-empty -m "update"')
+
+  silent PlugUpdate
+  Log getline(1, '$')
+  q
+
+  Assert !filereadable(g:plugs['vim-easy-align'].dir.'/failed'),
+    \ 'vim-easy-align/failed should not exist'
+  Assert filereadable(g:plugs['vim-pseudocl'].dir.'/not-failed'),
+    \ 'vim-pseudocl/not-failed should exist'
+
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 ~ Overriding `dir`
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