From debabe561a759c8fb1f2d26795fde60cd6d8fc5f Mon Sep 17 00:00:00 2001
From: Andrew Borodin <aborodin@vmail.ru>
Date: Sun, 26 Jun 2022 19:18:09 +0300
Subject: [PATCH] "file" utility: use -b option if available.

  * configure.ac: test if "file" utility has -b option.
  * (regex_check_type): don't compare file names if "file -b" is used.
Reduce variable scope. Rename variable.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
---
 configure.ac          | 19 +++++++++++++++++--
 src/filemanager/ext.c | 32 ++++++++++++++++++++------------
 2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/configure.ac b/configure.ac
index 044f04d56..e0292b436 100644
--- a/configure.ac
+++ b/configure.ac
@@ -126,7 +126,7 @@ fi
 AC_SUBST(MANDOC)
 AC_SUBST(MAN_FLAGS)
 
-dnl Check for -z, -L, and -S options to file
+dnl Check for -z, -b, -L, and -S options to file
 AC_CHECK_PROG(HAVE_FILECMD, file, true, false)
 if $HAVE_FILECMD; then
     dnl Don't use the file command if it doesn't accept the -z option
@@ -148,7 +148,22 @@ if $HAVE_FILECMD; then
     fi
 
     if test x$mc_cv_file_z = xyes; then
-        dnl file is used; check -L and -S options
+        dnl file is used; check -b, -L and -S options
+
+        AC_MSG_CHECKING([for -b option to file command])
+        AC_CACHE_VAL(mc_cv_file_b, [
+            file -b . > /dev/null 2>&1
+            if test $? = 0; then
+                mc_cv_file_b=yes
+            else
+                mc_cv_file_b=no
+            fi
+        ])
+        AC_MSG_RESULT([$mc_cv_file_b])
+
+        if test x$mc_cv_file_b = xyes; then
+            AC_DEFINE(FILE_B, "-b ", [Define if the file command accepts the -b option])
+        fi
 
         AC_MSG_CHECKING([for -L option to file command])
         AC_CACHE_VAL(mc_cv_file_L, [
diff --git a/src/filemanager/ext.c b/src/filemanager/ext.c
index 7d64beb42..43d0295dd 100644
--- a/src/filemanager/ext.c
+++ b/src/filemanager/ext.c
@@ -74,8 +74,12 @@
 /*** file scope macro definitions ****************************************************************/
 
 #ifdef USE_FILE_CMD
+#ifdef FILE_B
+#define FILE_CMD "file -z " FILE_B FILE_S FILE_L
+#else
 #define FILE_CMD "file -z " FILE_S FILE_L
 #endif
+#endif
 
 /*** file scope type declarations ****************************************************************/
 
@@ -646,7 +650,6 @@ regex_check_type (const vfs_path_t * filename_vpath, const char *ptr, gboolean c
     if (!*have_type)
     {
         vfs_path_t *localfile_vpath;
-        const char *realname;   /* name used with "file" */
 
 #ifdef HAVE_CHARSET
         static char encoding_id[21];    /* CSISO51INISCYRILLIC -- 20 */
@@ -664,7 +667,6 @@ regex_check_type (const vfs_path_t * filename_vpath, const char *ptr, gboolean c
             return FALSE;
         }
 
-        realname = vfs_path_get_last_path_str (localfile_vpath);
 
 #ifdef HAVE_CHARSET
         got_encoding_data = is_autodetect_codeset_enabled
@@ -694,26 +696,32 @@ regex_check_type (const vfs_path_t * filename_vpath, const char *ptr, gboolean c
         if (got_data > 0)
         {
             char *pp;
-            size_t real_len;
 
             pp = strchr (content_string, '\n');
             if (pp != NULL)
                 *pp = '\0';
 
-            real_len = strlen (realname);
-
-            if (strncmp (content_string, realname, real_len) == 0)
+#ifndef FILE_B
             {
-                /* Skip "realname: " */
-                content_shift = real_len;
-                if (content_string[content_shift] == ':')
+                const char *real_name;  /* name used with "file" */
+                size_t real_len;
+
+                real_name = vfs_path_get_last_path_str (localfile_vpath);
+                real_len = strlen (real_name);
+
+                if (strncmp (content_string, real_name, real_len) == 0)
                 {
+                    /* Skip "real_name: " */
+                    content_shift = real_len;
+
                     /* Solaris' file prints tab(s) after ':' */
-                    for (content_shift++; whitespace (content_string[content_shift]);
-                         content_shift++)
-                        ;
+                    if (content_string[content_shift] == ':')
+                        for (content_shift++; whitespace (content_string[content_shift]);
+                             content_shift++)
+                            ;
                 }
             }
+#endif /* FILE_B */
         }
         else
         {