patch 8.1.1371: cannot recover from a swap file

Problem:    Cannot recover from a swap file.
Solution:   Do not expand environment variables in the swap file name.
            Do not check the extension when we already know a file is a swap
            file.  (Ken Takata, closes 4415, closes #4369)

src/buffer.c

@@ -1071,7 +1071,7 @@ handle_swap_exists(bufref_T *old_curbuf)
 
 	/* User selected Recover at ATTENTION prompt. */
 	msg_scroll = TRUE;
-	ml_recover();
+	ml_recover(FALSE);
 	msg_puts("\n");	/* don't overwrite the last message */
 	cmdline_row = msg_row;
 	do_modelines(0);
@@ -4943,7 +4943,7 @@ do_arg_all(
 		    if (i < alist->al_ga.ga_len
 			    && (AARGLIST(alist)[i].ae_fnum == buf->b_fnum
 				|| fullpathcmp(alist_name(&AARGLIST(alist)[i]),
-					      buf->b_ffname, TRUE) & FPC_SAME))
+					buf->b_ffname, TRUE, TRUE) & FPC_SAME))
 		    {
 			int weight = 1;
 

src/ex_cmds.c

@@ -7002,7 +7002,8 @@ fix_help_buffer(void)
 		copy_option_part(&p, NameBuff, MAXPATHL, ",");
 		mustfree = FALSE;
 		rt = vim_getenv((char_u *)"VIMRUNTIME", &mustfree);
-		if (rt != NULL && fullpathcmp(rt, NameBuff, FALSE) != FPC_SAME)
+		if (rt != NULL &&
+			    fullpathcmp(rt, NameBuff, FALSE, TRUE) != FPC_SAME)
 		{
 		    int		fcount;
 		    char_u	**fnames;
@@ -7224,7 +7225,7 @@ helptags_one(
      */
     ga_init2(&ga, (int)sizeof(char_u *), 100);
     if (add_help_tags || fullpathcmp((char_u *)"$VIMRUNTIME/doc",
-						      dir, FALSE) == FPC_SAME)
+						dir, FALSE, TRUE) == FPC_SAME)
     {
 	if (ga_grow(&ga, 1) == FAIL)
 	    got_int = TRUE;

src/ex_cmds2.c

@@ -1715,7 +1715,7 @@ editing_arg_idx(win_T *win)
 		    && (win->w_buffer->b_ffname == NULL
 			 || !(fullpathcmp(
 				 alist_name(&WARGLIST(win)[win->w_arg_idx]),
-				win->w_buffer->b_ffname, TRUE) & FPC_SAME))));
+			  win->w_buffer->b_ffname, TRUE, TRUE) & FPC_SAME))));
 }
 
 /*
@@ -1737,7 +1737,7 @@ check_arg_idx(win_T *win)
 		&& (win->w_buffer->b_fnum == GARGLIST[GARGCOUNT - 1].ae_fnum
 		    || (win->w_buffer->b_ffname != NULL
 			&& (fullpathcmp(alist_name(&GARGLIST[GARGCOUNT - 1]),
-				win->w_buffer->b_ffname, TRUE) & FPC_SAME))))
+			  win->w_buffer->b_ffname, TRUE, TRUE) & FPC_SAME))))
 	    arg_had_last = TRUE;
     }
     else

src/ex_docmd.c

@@ -6725,7 +6725,7 @@ ex_recover(exarg_T *eap)
 
 	    && (*eap->arg == NUL
 			     || setfname(curbuf, eap->arg, NULL, TRUE) == OK))
-	ml_recover();
+	ml_recover(TRUE);
     recoverymode = FALSE;
 }
 

src/gui.c

@@ -603,22 +603,22 @@ gui_init(void)
 #endif
 
 		if (       fullpathcmp((char_u *)USR_GVIMRC_FILE,
-				     (char_u *)GVIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)GVIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #ifdef SYS_GVIMRC_FILE
 			&& fullpathcmp((char_u *)SYS_GVIMRC_FILE,
-				     (char_u *)GVIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)GVIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 #ifdef USR_GVIMRC_FILE2
 			&& fullpathcmp((char_u *)USR_GVIMRC_FILE2,
-				     (char_u *)GVIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)GVIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 #ifdef USR_GVIMRC_FILE3
 			&& fullpathcmp((char_u *)USR_GVIMRC_FILE3,
-				     (char_u *)GVIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)GVIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 #ifdef USR_GVIMRC_FILE4
 			&& fullpathcmp((char_u *)USR_GVIMRC_FILE4,
-				     (char_u *)GVIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)GVIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 			)
 		    do_source((char_u *)GVIMRC_FILE, TRUE, DOSO_GVIMRC);

src/if_cscope.c

@@ -1401,10 +1401,10 @@ cs_insert_filelist(
 #if defined(UNIX)
 	    && csinfo[j].st_dev == sb->st_dev && csinfo[j].st_ino == sb->st_ino
 #else
-	    /* compare pathnames first */
+	    // compare pathnames first
 	    && ((fullpathcmp((char_u *)csinfo[j].fname,
-			(char_u *)fname, FALSE) & FPC_SAME)
+			(char_u *)fname, FALSE, TRUE) & FPC_SAME)
-		/* test index file attributes too */
+		// test index file attributes too
 		|| (csinfo[j].nVolume == bhfi.dwVolumeSerialNumber
 		    && csinfo[j].nIndexHigh == bhfi.nFileIndexHigh
 		    && csinfo[j].nIndexLow == bhfi.nFileIndexLow))

src/main.c

@@ -2684,7 +2684,7 @@ create_windows(mparm_T *parmp UNUSED)
     if (recoverymode)			/* do recover */
     {
 	msg_scroll = TRUE;		/* scroll message up */
-	ml_recover();
+	ml_recover(TRUE);
 	if (curbuf->b_ml.ml_mfp == NULL) /* failed */
 	    getout(1);
 	do_modelines(0);		/* do modelines */
@@ -3101,18 +3101,18 @@ source_startup_scripts(mparm_T *parmp)
 
 	    i = FAIL;
 	    if (fullpathcmp((char_u *)USR_VIMRC_FILE,
-				      (char_u *)VIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)VIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #ifdef USR_VIMRC_FILE2
 		    && fullpathcmp((char_u *)USR_VIMRC_FILE2,
-				      (char_u *)VIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)VIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 #ifdef USR_VIMRC_FILE3
 		    && fullpathcmp((char_u *)USR_VIMRC_FILE3,
-				      (char_u *)VIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)VIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 #ifdef SYS_VIMRC_FILE
 		    && fullpathcmp((char_u *)SYS_VIMRC_FILE,
-				      (char_u *)VIMRC_FILE, FALSE) != FPC_SAME
+				(char_u *)VIMRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 				)
 		i = do_source((char_u *)VIMRC_FILE, TRUE, DOSO_VIMRC);
@@ -3127,10 +3127,10 @@ source_startup_scripts(mparm_T *parmp)
 		    secure = 0;
 #endif
 		if (	   fullpathcmp((char_u *)USR_EXRC_FILE,
-				      (char_u *)EXRC_FILE, FALSE) != FPC_SAME
+				(char_u *)EXRC_FILE, FALSE, TRUE) != FPC_SAME
 #ifdef USR_EXRC_FILE2
 			&& fullpathcmp((char_u *)USR_EXRC_FILE2,
-				      (char_u *)EXRC_FILE, FALSE) != FPC_SAME
+				(char_u *)EXRC_FILE, FALSE, TRUE) != FPC_SAME
 #endif
 				)
 		    (void)do_source((char_u *)EXRC_FILE, FALSE, DOSO_NONE);

src/memline.c

@@ -1084,9 +1084,11 @@ add_b0_fenc(
 
 /*
  * Try to recover curbuf from the .swp file.
+ * If "checkext" is TRUE, check the extension and detect whether it is
+ * a swap file.
  */
     void
-ml_recover(void)
+ml_recover(int checkext)
 {
     buf_T	*buf = NULL;
     memfile_T	*mfp = NULL;
@@ -1136,7 +1138,7 @@ ml_recover(void)
     if (fname == NULL)		    /* When there is no file name */
 	fname = (char_u *)"";
     len = (int)STRLEN(fname);
-    if (len >= 4 &&
+    if (checkext && len >= 4 &&
 #if defined(VMS)
 	    STRNICMP(fname + len - 4, "_s", 2)
 #else
@@ -1887,7 +1889,7 @@ recover_names(
 	if (num_names == 0)
 	    num_files = 0;
 	else if (expand_wildcards(num_names, names, &num_files, &files,
-					EW_KEEPALL|EW_FILE|EW_SILENT) == FAIL)
+			    EW_NOTENV|EW_KEEPALL|EW_FILE|EW_SILENT) == FAIL)
 	    num_files = 0;
 
 	/*
@@ -1930,11 +1932,13 @@ recover_names(
 			       && (p = curbuf->b_ml.ml_mfp->mf_fname) != NULL)
 	{
 	    for (i = 0; i < num_files; ++i)
-		if (fullpathcmp(p, files[i], TRUE) & FPC_SAME)
+		// Do not expand wildcards, on windows would try to expand
+		// "%tmp%" in "%tmp%file".
+		if (fullpathcmp(p, files[i], TRUE, FALSE) & FPC_SAME)
 		{
-		    /* Remove the name from files[i].  Move further entries
+		    // Remove the name from files[i].  Move further entries
-		     * down.  When the array becomes empty free it here, since
+		    // down.  When the array becomes empty free it here, since
-		     * FreeWild() won't be called below. */
+		    // FreeWild() won't be called below.
 		    vim_free(files[i]);
 		    if (--num_files == 0)
 			vim_free(files);

src/misc1.c

@@ -2691,13 +2691,15 @@ home_replace_save(
  * FPC_DIFF   if they both exist and are different files.
  * FPC_NOTX   if they both don't exist.
  * FPC_DIFFX  if one of them doesn't exist.
- * For the first name environment variables are expanded
+ * For the first name environment variables are expanded if "expandenv" is
+ * TRUE.
  */
     int
 fullpathcmp(
     char_u *s1,
     char_u *s2,
-    int	    checkname)		/* when both don't exist, check file names */
+    int	    checkname,		// when both don't exist, check file names
+    int	    expandenv)
 {
 #ifdef UNIX
     char_u	    exp1[MAXPATHL];
@@ -2706,7 +2708,10 @@ fullpathcmp(
     stat_T	    st1, st2;
     int		    r1, r2;
 
+    if (expandenv)
 	expand_env(s1, exp1, MAXPATHL);
+    else
+	vim_strncpy(exp1, s1, MAXPATHL - 1);
     r1 = mch_stat((char *)exp1, &st1);
     r2 = mch_stat((char *)s2, &st2);
     if (r1 != 0 && r2 != 0)
@@ -2741,7 +2746,10 @@ fullpathcmp(
 	full1 = exp1 + MAXPATHL;
 	full2 = full1 + MAXPATHL;
 
+	if (expandenv)
 	    expand_env(s1, exp1, MAXPATHL);
+	else
+	    vim_strncpy(exp1, s1, MAXPATHL - 1);
 	r1 = vim_FullName(exp1, full1, MAXPATHL, FALSE);
 	r2 = vim_FullName(s2, full2, MAXPATHL, FALSE);
 
@@ -4027,7 +4035,7 @@ gen_expand_wildcards(
 	    /*
 	     * First expand environment variables, "~/" and "~user/".
 	     */
-	    if (has_env_var(p) || *p == '~')
+	    if ((has_env_var(p) && !(flags & EW_NOTENV)) || *p == '~')
 	    {
 		p = expand_env_save_opt(p, TRUE);
 		if (p == NULL)

src/proto/memline.pro

@@ -9,7 +9,7 @@ void ml_close(buf_T *buf, int del_file);
 void ml_close_all(int del_file);
 void ml_close_notmod(void);
 void ml_timestamp(buf_T *buf);
-void ml_recover(void);
+void ml_recover(int checkext);
 int recover_names(char_u *fname, int list, int nr, char_u **fname_out);
 char_u *make_percent_swname(char_u *dir, char_u *name);
 void get_b0_dict(char_u *fname, dict_T *d);

src/proto/misc1.pro

@@ -45,7 +45,7 @@ char_u *get_users(expand_T *xp, int idx);
 int match_user(char_u *name);
 void home_replace(buf_T *buf, char_u *src, char_u *dst, int dstlen, int one);
 char_u *home_replace_save(buf_T *buf, char_u *src);
-int fullpathcmp(char_u *s1, char_u *s2, int checkname);
+int fullpathcmp(char_u *s1, char_u *s2, int checkname, int expandenv);
 char_u *gettail(char_u *fname);
 char_u *gettail_sep(char_u *fname);
 char_u *getnextcomp(char_u *fname);

src/search.c

@@ -5170,7 +5170,8 @@ find_pattern_in_path(
 			i = old_files;
 		    if (i == max_path_depth)
 			break;
-		    if (fullpathcmp(new_fname, files[i].name, TRUE) & FPC_SAME)
+		    if (fullpathcmp(new_fname, files[i].name, TRUE, TRUE)
+								    & FPC_SAME)
 		    {
 			if (type != CHECK_PATH &&
 				action == ACTION_SHOW_ALL && files[i].matched)

src/spell.c

@@ -2343,7 +2343,7 @@ did_set_spelllang(win_T *wp)
 
 	    /* Check if we loaded this language before. */
 	    for (slang = first_lang; slang != NULL; slang = slang->sl_next)
-		if (fullpathcmp(lang, slang->sl_fname, FALSE) == FPC_SAME)
+		if (fullpathcmp(lang, slang->sl_fname, FALSE, TRUE) == FPC_SAME)
 		    break;
 	}
 	else
@@ -2395,7 +2395,8 @@ did_set_spelllang(win_T *wp)
 	 * Loop over the languages, there can be several files for "lang".
 	 */
 	for (slang = first_lang; slang != NULL; slang = slang->sl_next)
-	    if (filename ? fullpathcmp(lang, slang->sl_fname, FALSE) == FPC_SAME
+	    if (filename ? fullpathcmp(lang, slang->sl_fname, FALSE, TRUE)
+								    == FPC_SAME
 			 : STRICMP(lang, slang->sl_name) == 0)
 	    {
 		region_mask = REGION_ALL;
@@ -2463,7 +2464,8 @@ did_set_spelllang(win_T *wp)
 	    for (c = 0; c < ga.ga_len; ++c)
 	    {
 		p = LANGP_ENTRY(ga, c)->lp_slang->sl_fname;
-		if (p != NULL && fullpathcmp(spf_name, p, FALSE) == FPC_SAME)
+		if (p != NULL && fullpathcmp(spf_name, p, FALSE, TRUE)
+								== FPC_SAME)
 		    break;
 	    }
 	    if (c < ga.ga_len)
@@ -2472,7 +2474,8 @@ did_set_spelllang(win_T *wp)
 
 	/* Check if it was loaded already. */
 	for (slang = first_lang; slang != NULL; slang = slang->sl_next)
-	    if (fullpathcmp(spf_name, slang->sl_fname, FALSE) == FPC_SAME)
+	    if (fullpathcmp(spf_name, slang->sl_fname, FALSE, TRUE)
+								== FPC_SAME)
 		break;
 	if (slang == NULL)
 	{

src/spellfile.c

@@ -1734,7 +1734,7 @@ spell_reload_one(
 
     for (slang = first_lang; slang != NULL; slang = slang->sl_next)
     {
-	if (fullpathcmp(fname, slang->sl_fname, FALSE) == FPC_SAME)
+	if (fullpathcmp(fname, slang->sl_fname, FALSE, TRUE) == FPC_SAME)
 	{
 	    slang_clear(slang);
 	    if (spell_load_file(fname, NULL, slang, FALSE) == NULL)
@@ -5440,7 +5440,7 @@ spell_make_sugfile(spellinfo_T *spin, char_u *wfname)
      * It might have been done already by spell_reload_one().
      */
     for (slang = first_lang; slang != NULL; slang = slang->sl_next)
-	if (fullpathcmp(wfname, slang->sl_fname, FALSE) == FPC_SAME)
+	if (fullpathcmp(wfname, slang->sl_fname, FALSE, TRUE) == FPC_SAME)
 	    break;
     if (slang == NULL)
     {

src/tag.c

@@ -3781,7 +3781,7 @@ test_for_current(
 	fullname = expand_tag_fname(fname, tag_fname, TRUE);
 	if (fullname != NULL)
 	{
-	    retval = (fullpathcmp(fullname, buf_ffname, TRUE) & FPC_SAME);
+	    retval = (fullpathcmp(fullname, buf_ffname, TRUE, TRUE) & FPC_SAME);
 	    vim_free(fullname);
 	}
 #ifdef FEAT_EMACS_TAGS

src/testdir/test_swap.vim

@@ -220,3 +220,87 @@ func Test_swapfile_delete()
   augroup END
   augroup! test_swapfile_delete
 endfunc
+
+func Test_swap_recover()
+  autocmd! SwapExists
+  augroup test_swap_recover
+    autocmd!
+    autocmd SwapExists * let v:swapchoice = 'r'
+  augroup END
+
+
+  call mkdir('Xswap')
+  let $Xswap = 'foo'  " Check for issue #4369.
+  set dir=Xswap//
+  " Create a valid swapfile by editing a file.
+  split Xswap/text
+  call setline(1, ['one', 'two', 'three'])
+  write  " file is written, not modified
+  " read the swapfile as a Blob
+  let swapfile_name = swapname('%')
+  let swapfile_bytes = readfile(swapfile_name, 'B')
+
+  " Close the file and recreate the swap file.
+  quit
+  call writefile(swapfile_bytes, swapfile_name)
+  " Edit the file again. This triggers recovery.
+  try
+    split Xswap/text
+  catch
+    " E308 should be caught, not E305.
+    call assert_exception('E308:')  " Original file may have been changed
+  endtry
+  " The file should be recovered.
+  call assert_equal(['one', 'two', 'three'], getline(1, 3))
+  quit!
+
+  call delete('Xswap/text')
+  call delete(swapfile_name)
+  call delete('Xswap', 'd')
+  unlet $Xswap
+  set dir&
+  augroup test_swap_recover
+    autocmd!
+  augroup END
+  augroup! test_swap_recover
+endfunc
+
+func Test_swap_recover_ext()
+  autocmd! SwapExists
+  augroup test_swap_recover_ext
+    autocmd!
+    autocmd SwapExists * let v:swapchoice = 'r'
+  augroup END
+
+
+  " Create a valid swapfile by editing a file with a special extension.
+  split Xtest.scr
+  call setline(1, ['one', 'two', 'three'])
+  write  " file is written, not modified
+  write  " write again to make sure the swapfile is created
+  " read the swapfile as a Blob
+  let swapfile_name = swapname('%')
+  let swapfile_bytes = readfile(swapfile_name, 'B')
+
+  " Close and delete the file and recreate the swap file.
+  quit
+  call delete('Xtest.scr')
+  call writefile(swapfile_bytes, swapfile_name)
+  " Edit the file again. This triggers recovery.
+  try
+    split Xtest.scr
+  catch
+    " E308 should be caught, not E306.
+    call assert_exception('E308:')  " Original file may have been changed
+  endtry
+  " The file should be recovered.
+  call assert_equal(['one', 'two', 'three'], getline(1, 3))
+  quit!
+
+  call delete('Xtest.scr')
+  call delete(swapfile_name)
+  augroup test_swap_recover_ext
+    autocmd!
+  augroup END
+  augroup! test_swap_recover_ext
+endfunc

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1371,
 /**/
     1370,
 /**/

src/vim.h

@@ -781,26 +781,27 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 #define WILD_ICASE		0x100
 #define WILD_ALLLINKS		0x200
 
-/* Flags for expand_wildcards() */
+// Flags for expand_wildcards()
-#define EW_DIR		0x01	/* include directory names */
+#define EW_DIR		0x01	// include directory names
-#define EW_FILE		0x02	/* include file names */
+#define EW_FILE		0x02	// include file names
-#define EW_NOTFOUND	0x04	/* include not found names */
+#define EW_NOTFOUND	0x04	// include not found names
-#define EW_ADDSLASH	0x08	/* append slash to directory name */
+#define EW_ADDSLASH	0x08	// append slash to directory name
-#define EW_KEEPALL	0x10	/* keep all matches */
+#define EW_KEEPALL	0x10	// keep all matches
-#define EW_SILENT	0x20	/* don't print "1 returned" from shell */
+#define EW_SILENT	0x20	// don't print "1 returned" from shell
-#define EW_EXEC		0x40	/* executable files */
+#define EW_EXEC		0x40	// executable files
-#define EW_PATH		0x80	/* search in 'path' too */
+#define EW_PATH		0x80	// search in 'path' too
-#define EW_ICASE	0x100	/* ignore case */
+#define EW_ICASE	0x100	// ignore case
-#define EW_NOERROR	0x200	/* no error for bad regexp */
+#define EW_NOERROR	0x200	// no error for bad regexp
-#define EW_NOTWILD	0x400	/* add match with literal name if exists */
+#define EW_NOTWILD	0x400	// add match with literal name if exists
-#define EW_KEEPDOLLAR	0x800	/* do not escape $, $var is expanded */
+#define EW_KEEPDOLLAR	0x800	// do not escape $, $var is expanded
-/* Note: mostly EW_NOTFOUND and EW_SILENT are mutually exclusive: EW_NOTFOUND
+// Note: mostly EW_NOTFOUND and EW_SILENT are mutually exclusive: EW_NOTFOUND
- * is used when executing commands and EW_SILENT for interactive expanding. */
+// is used when executing commands and EW_SILENT for interactive expanding.
-#define EW_ALLLINKS	0x1000	/* also links not pointing to existing file */
+#define EW_ALLLINKS	0x1000	// also links not pointing to existing file
-#define EW_SHELLCMD	0x2000	/* called from expand_shellcmd(), don't check
+#define EW_SHELLCMD	0x2000	// called from expand_shellcmd(), don't check
-				 * if executable is in $PATH */
+				// if executable is in $PATH
-#define EW_DODOT	0x4000	/* also files starting with a dot */
+#define EW_DODOT	0x4000	// also files starting with a dot
-#define EW_EMPTYOK	0x8000	/* no matches is not an error */
+#define EW_EMPTYOK	0x8000	// no matches is not an error
+#define EW_NOTENV	0x10000	// do not expand environment variables
 
 /* Flags for find_file_*() functions. */
 #define FINDFILE_FILE	0	/* only files */