commit 6e5a9f948221b52caaaf106079cb3430c4dd7c77
author Federico Mengozzi <19249682+fedemengo@users.noreply.github.com> Mon Apr 17 22:31:38 2023 +0100
committer Bram Moolenaar <Bram@vim.org> Mon Apr 17 22:31:38 2023 +0100
tree e22fbc7d41e12e87de97afdaff9dc24f34f04ad5
parent 4c42c7eef43ff0f58fa574f7a900c8a3313f372e

patch 9.0.1464: strace filetype detection is expensive

Problem:    Strace filetype detection is expensive.
Solution:   Match with a cheap pattern first. (Federico Mengozzi,
            closes #12220)

runtime/autoload/dist/script.vim

diff --git a/runtime/autoload/dist/script.vim b/runtime/autoload/dist/script.vim
index f86c428..e95c633 100644
--- a/runtime/autoload/dist/script.vim
+++ b/runtime/autoload/dist/script.vim
@@ -338,7 +338,9 @@
     set ft=virata
 
     # Strace
-  elseif line1 =~ '[0-9:.]* *execve(' || line1 =~ '^__libc_start_main'
+    # inaccurate fast match first, then use accurate slow match
+  elseif (line1 =~ 'execve(' && line1 =~ '^[0-9:.]* *execve(')
+	   || line1 =~ '^__libc_start_main'
     set ft=strace
 
     # VSE JCL

src/testdir/test_filetype.vim

diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 0b8b52c..60e4f30 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -733,6 +733,11 @@
   filetype off
 endfunc
 
+" Content lines that should not result in filetype detection
+let s:false_positive_checks = {
+      \ '': [['test execve("/usr/bin/pstree", ["pstree"], 0x7ff0 /* 63 vars */) = 0']],
+      \ }
+
 " Filetypes detected from the file contents by scripts.vim
 let s:script_checks = {
       \ 'virata': [['% Virata'],
@@ -824,6 +829,7 @@
 endfunc
 
 func Test_script_detection()
+  call Run_script_detection(s:false_positive_checks)
   call Run_script_detection(s:script_checks)
   call Run_script_detection(s:script_env_checks)
 endfunc

src/version.c

diff --git a/src/version.c b/src/version.c
index 6c8d76e..c050afe 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1464,
+/**/
     1463,
 /**/
     1462,