Re: BUG #16059: Tab-completion of filenames in COPY commands removes required quotes - Mailing list pgsql-hackers

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> One minor thing I noticed is that if I enter
> \copy t from '/tmp/t'<tab>
> and I have files /tmp/t and /tmp/tst then it removes the ending quote.

Yeah, that bothered me too.  [ pokes at it for a bit... ]  The
quote_file_name function isn't passed enough info to handle this
in a clean way, but we can make it work if we don't mind introducing
some more coupling with psql_completion, ie having the latter remember
whether the raw input word ended with a quote.  As per v4.

> (The unpatched version removes *both* quotes.  The quotes there are not
> mandatory, but the new version works better when there are files with
> whitespace in the name.)

Or when you're completing in a COPY rather than \copy --- then, removing
the quotes is broken whether there's whitespace or not.

            regards, tom lane

diff --git a/config/programs.m4 b/config/programs.m4
index 90ff944..68ab823 100644
--- a/config/programs.m4
+++ b/config/programs.m4
@@ -209,17 +209,20 @@ fi



-# PGAC_VAR_RL_COMPLETION_APPEND_CHARACTER
-# ---------------------------------------
+# PGAC_READLINE_VARIABLES
+# -----------------------
 # Readline versions < 2.1 don't have rl_completion_append_character
+# Libedit lacks rl_filename_quote_characters and rl_filename_quoting_function

-AC_DEFUN([PGAC_VAR_RL_COMPLETION_APPEND_CHARACTER],
+AC_DEFUN([PGAC_READLINE_VARIABLES],
 [AC_CACHE_CHECK([for rl_completion_append_character], pgac_cv_var_rl_completion_append_character,
 [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>
-#ifdef HAVE_READLINE_READLINE_H
-# include <readline/readline.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
 #elif defined(HAVE_READLINE_H)
-# include <readline.h>
+#include <readline.h>
 #endif
 ],
 [rl_completion_append_character = 'x';])],
@@ -228,7 +231,42 @@ AC_DEFUN([PGAC_VAR_RL_COMPLETION_APPEND_CHARACTER],
 if test x"$pgac_cv_var_rl_completion_append_character" = x"yes"; then
 AC_DEFINE(HAVE_RL_COMPLETION_APPEND_CHARACTER, 1,
           [Define to 1 if you have the global variable 'rl_completion_append_character'.])
-fi])# PGAC_VAR_RL_COMPLETION_APPEND_CHARACTER
+fi
+AC_CACHE_CHECK([for rl_filename_quote_characters], pgac_cv_var_rl_filename_quote_characters,
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
+#elif defined(HAVE_READLINE_H)
+#include <readline.h>
+#endif
+],
+[rl_filename_quote_characters = "x";])],
+[pgac_cv_var_rl_filename_quote_characters=yes],
+[pgac_cv_var_rl_filename_quote_characters=no])])
+if test x"$pgac_cv_var_rl_filename_quote_characters" = x"yes"; then
+AC_DEFINE(HAVE_RL_FILENAME_QUOTE_CHARACTERS, 1,
+          [Define to 1 if you have the global variable 'rl_filename_quote_characters'.])
+fi
+AC_CACHE_CHECK([for rl_filename_quoting_function], pgac_cv_var_rl_filename_quoting_function,
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
+#elif defined(HAVE_READLINE_H)
+#include <readline.h>
+#endif
+],
+[rl_filename_quoting_function = 0;])],
+[pgac_cv_var_rl_filename_quoting_function=yes],
+[pgac_cv_var_rl_filename_quoting_function=no])])
+if test x"$pgac_cv_var_rl_filename_quoting_function" = x"yes"; then
+AC_DEFINE(HAVE_RL_FILENAME_QUOTING_FUNCTION, 1,
+          [Define to 1 if you have the global variable 'rl_filename_quoting_function'.])
+fi
+])# PGAC_READLINE_VARIABLES



diff --git a/configure b/configure
index 9de5037..994e736 100755
--- a/configure
+++ b/configure
@@ -16314,10 +16314,12 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_READLINE_READLINE_H
-# include <readline/readline.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
 #elif defined(HAVE_READLINE_H)
-# include <readline.h>
+#include <readline.h>
 #endif

 int
@@ -16343,6 +16345,85 @@ if test x"$pgac_cv_var_rl_completion_append_character" = x"yes"; then
 $as_echo "#define HAVE_RL_COMPLETION_APPEND_CHARACTER 1" >>confdefs.h

 fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for rl_filename_quote_characters" >&5
+$as_echo_n "checking for rl_filename_quote_characters... " >&6; }
+if ${pgac_cv_var_rl_filename_quote_characters+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdio.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
+#elif defined(HAVE_READLINE_H)
+#include <readline.h>
+#endif
+
+int
+main ()
+{
+rl_filename_quote_characters = "x";
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv_var_rl_filename_quote_characters=yes
+else
+  pgac_cv_var_rl_filename_quote_characters=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_var_rl_filename_quote_characters" >&5
+$as_echo "$pgac_cv_var_rl_filename_quote_characters" >&6; }
+if test x"$pgac_cv_var_rl_filename_quote_characters" = x"yes"; then
+
+$as_echo "#define HAVE_RL_FILENAME_QUOTE_CHARACTERS 1" >>confdefs.h
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for rl_filename_quoting_function" >&5
+$as_echo_n "checking for rl_filename_quoting_function... " >&6; }
+if ${pgac_cv_var_rl_filename_quoting_function+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdio.h>
+#if defined(HAVE_READLINE_READLINE_H)
+#include <readline/readline.h>
+#elif defined(HAVE_EDITLINE_READLINE_H)
+#include <editline/readline.h>
+#elif defined(HAVE_READLINE_H)
+#include <readline.h>
+#endif
+
+int
+main ()
+{
+rl_filename_quoting_function = 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv_var_rl_filename_quoting_function=yes
+else
+  pgac_cv_var_rl_filename_quoting_function=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_var_rl_filename_quoting_function" >&5
+$as_echo "$pgac_cv_var_rl_filename_quoting_function" >&6; }
+if test x"$pgac_cv_var_rl_filename_quoting_function" = x"yes"; then
+
+$as_echo "#define HAVE_RL_FILENAME_QUOTING_FUNCTION 1" >>confdefs.h
+
+fi
+
   for ac_func in rl_completion_matches rl_filename_completion_function rl_reset_screen_size
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
diff --git a/configure.in b/configure.in
index 9c5e5e7..0921262 100644
--- a/configure.in
+++ b/configure.in
@@ -1873,7 +1873,7 @@ fi
 LIBS="$LIBS_including_readline"

 if test "$with_readline" = yes; then
-  PGAC_VAR_RL_COMPLETION_APPEND_CHARACTER
+  PGAC_READLINE_VARIABLES
   AC_CHECK_FUNCS([rl_completion_matches rl_filename_completion_function rl_reset_screen_size])
   AC_CHECK_FUNCS([append_history history_truncate_file])
 fi
diff --git a/src/bin/psql/stringutils.c b/src/bin/psql/stringutils.c
index 8c8b4c2..23a6f9f 100644
--- a/src/bin/psql/stringutils.c
+++ b/src/bin/psql/stringutils.c
@@ -282,6 +282,7 @@ strip_quotes(char *source, char quote, char escape, int encoding)
  * entails_quote -    any of these present?  need outer quotes
  * quote -            doubled within string, affixed to both ends
  * escape -            doubled within string
+ * force_quote -    if true, quote the output even if it doesn't "need" it
  * encoding -        the active character-set encoding
  *
  * Do not use this as a substitute for PQescapeStringConn().  Use it for
@@ -289,12 +290,13 @@ strip_quotes(char *source, char quote, char escape, int encoding)
  */
 char *
 quote_if_needed(const char *source, const char *entails_quote,
-                char quote, char escape, int encoding)
+                char quote, char escape, bool force_quote,
+                int encoding)
 {
     const char *src;
     char       *ret;
     char       *dst;
-    bool        need_quotes = false;
+    bool        need_quotes = force_quote;

     Assert(source != NULL);
     Assert(quote != '\0');
diff --git a/src/bin/psql/stringutils.h b/src/bin/psql/stringutils.h
index 16a7af0..fa00141 100644
--- a/src/bin/psql/stringutils.h
+++ b/src/bin/psql/stringutils.h
@@ -22,6 +22,7 @@ extern char *strtokx(const char *s,
 extern void strip_quotes(char *source, char quote, char escape, int encoding);

 extern char *quote_if_needed(const char *source, const char *entails_quote,
-                             char quote, char escape, int encoding);
+                             char quote, char escape, bool force_quote,
+                             int encoding);

 #endif                            /* STRINGUTILS_H */
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 5e0db35..3071f41 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -41,6 +41,7 @@
 #ifdef USE_READLINE

 #include <ctype.h>
+#include <sys/stat.h>

 #include "catalog/pg_am_d.h"
 #include "catalog/pg_class_d.h"
@@ -63,6 +64,15 @@
 #define rl_completion_matches completion_matches
 #endif

+/*
+ * Currently we assume that rl_filename_dequoting_function exists if
+ * rl_filename_quoting_function does.  If that proves not to be the case,
+ * we'd need to test for the former, or possibly both, in configure.
+ */
+#ifdef HAVE_RL_FILENAME_QUOTING_FUNCTION
+#define USE_FILENAME_QUOTING_FUNCTIONS 1
+#endif
+
 /* word break characters */
 #define WORD_BREAKS        "\t\n@$><=;|&{() "

@@ -157,9 +167,11 @@ typedef struct SchemaQuery
 static int    completion_max_records;

 /*
- * Communication variables set by COMPLETE_WITH_FOO macros and then used by
- * the completion callback functions.  Ugly but there is no better way.
+ * Communication variables set by psql_completion (mostly in COMPLETE_WITH_FOO
+ * macros) and then used by the completion callback functions.  Ugly but there
+ * is no better way.
  */
+static char completion_last_char;    /* last char of input word */
 static const char *completion_charp;    /* to pass a string */
 static const char *const *completion_charpp;    /* to pass a list of strings */
 static const char *completion_info_charp;    /* to pass a second string */
@@ -1114,9 +1126,9 @@ static char **get_previous_words(int point, char **buffer, int *nwords);

 static char *get_guctype(const char *varname);

-#ifdef NOT_USED
-static char *quote_file_name(char *text, int match_type, char *quote_pointer);
-static char *dequote_file_name(char *text, char quote_char);
+#ifdef USE_FILENAME_QUOTING_FUNCTIONS
+static char *quote_file_name(char *fname, int match_type, char *quote_pointer);
+static char *dequote_file_name(char *fname, int quote_char);
 #endif


@@ -1129,8 +1141,32 @@ initialize_readline(void)
     rl_readline_name = (char *) pset.progname;
     rl_attempted_completion_function = psql_completion;

+#ifdef USE_FILENAME_QUOTING_FUNCTIONS
+    rl_filename_quoting_function = quote_file_name;
+    rl_filename_dequoting_function = dequote_file_name;
+#endif
+
     rl_basic_word_break_characters = WORD_BREAKS;

+    rl_completer_quote_characters = "'\"";
+
+    /*
+     * Set rl_filename_quote_characters to "all possible characters",
+     * otherwise Readline will skip filename quoting if it thinks a filename
+     * doesn't need quoting.  Readline actually interprets this as bytes, so
+     * there are no encoding considerations here.
+     */
+#ifdef HAVE_RL_FILENAME_QUOTE_CHARACTERS
+    {
+        unsigned char *fqc = (unsigned char *) pg_malloc(256);
+
+        for (int i = 0; i < 255; i++)
+            fqc[i] = (unsigned char) (i + 1);
+        fqc[255] = '\0';
+        rl_filename_quote_characters = (const char *) fqc;
+    }
+#endif
+
     completion_max_records = 1000;

     /*
@@ -1447,8 +1483,10 @@ psql_completion(const char *text, int start, int end)
         NULL
     };

-    (void) end;                    /* "end" is not used */
+    /* Remember last char of the given input word. */
+    completion_last_char = (end > start) ? text[end - start - 1] : '\0';

+    /* We usually want the append character to be a space. */
 #ifdef HAVE_RL_COMPLETION_APPEND_CHARACTER
     rl_completion_append_character = ' ';
 #endif
@@ -4378,15 +4416,49 @@ complete_from_variables(const char *text, const char *prefix, const char *suffix

 /*
  * This function wraps rl_filename_completion_function() to strip quotes from
- * the input before searching for matches and to quote any matches for which
- * the consuming command will require it.
+ * the input before searching for matches and then re-quote the matches.
+ * (We always quote filenames, even though for some psql meta-commands and
+ * some filenames it wouldn't be strictly necessary.)
+ *
+ * Caller must set completion_charp to a zero- or one-character string
+ * containing the escape character.  This is necessary since \copy has no
+ * escape character, but every other backslash command recognizes "\" as an
+ * escape character.  Since we have only two callers, don't bother providing
+ * a macro to simplify this.
  */
 static char *
 complete_from_files(const char *text, int state)
 {
+#ifdef USE_FILENAME_QUOTING_FUNCTIONS
+    /*
+     * If we're using a version of Readline that supports filename quoting
+     * hooks, rely on those, and invoke rl_filename_completion_function()
+     * without messing with its arguments.  Readline does stuff internally
+     * that does not work well at all if we try to handle dequoting here.
+     * Instead, Readline will call quote_file_name() and dequote_file_name()
+     * (see below) at appropriate times.
+     *
+     * ... or at least, mostly it will.  There are some paths involving
+     * unmatched file names in which Readline never calls quote_file_name(),
+     * and if left to its own devices it will incorrectly append a quote
+     * anyway.  Set rl_completion_suppress_quote to prevent that.  If we do
+     * get to quote_file_name(), we'll clear this again.  (Yes, this seems
+     * like it's working around Readline bugs.)
+     *
+     * (For now, we assume that rl_completion_suppress_quote exists if the
+     * filename quoting hooks do.)
+     */
+    rl_completion_suppress_quote = 1;
+
+    return rl_filename_completion_function(text, state);
+#else
+    /*
+     * Otherwise, we have to do the best we can.
+     */
     static const char *unquoted_text;
     char       *unquoted_match;
     char       *ret = NULL;
+    struct stat statbuf;

     if (state == 0)
     {
@@ -4404,22 +4476,36 @@ complete_from_files(const char *text, int state)
     unquoted_match = rl_filename_completion_function(unquoted_text, state);
     if (unquoted_match)
     {
+        /* Re-quote the result. */
+        ret = quote_if_needed(unquoted_match, " \t\r\n\"`",
+                              '\'', *completion_charp,
+                              true,
+                              pset.encoding);
+        Assert(ret);
+
         /*
-         * Caller sets completion_charp to a zero- or one-character string
-         * containing the escape character.  This is necessary since \copy has
-         * no escape character, but every other backslash command recognizes
-         * "\" as an escape character.  Since we have only two callers, don't
-         * bother providing a macro to simplify this.
+         * If it's a directory, replace trailing quote with a slash; this is
+         * usually more convenient.
          */
-        ret = quote_if_needed(unquoted_match, " \t\r\n\"`",
-                              '\'', *completion_charp, pset.encoding);
-        if (ret)
-            free(unquoted_match);
-        else
-            ret = unquoted_match;
+        if (*ret &&
+            stat(unquoted_match, &statbuf) == 0 &&
+            S_ISDIR(statbuf.st_mode))
+        {
+            char       *retend = ret + strlen(ret) - 1;
+
+            Assert(*retend == '\'');
+            *retend = '/';
+            /* Try to prevent libedit from adding a space, too */
+#ifdef HAVE_RL_COMPLETION_APPEND_CHARACTER
+            rl_completion_append_character = '\0';
+#endif
+        }
+
+        free(unquoted_match);
     }

     return ret;
+#endif                            /* USE_FILENAME_QUOTING_FUNCTIONS */
 }


@@ -4671,46 +4757,106 @@ get_guctype(const char *varname)
     return guctype;
 }

-#ifdef NOT_USED
+#ifdef USE_FILENAME_QUOTING_FUNCTIONS

 /*
- * Surround a string with single quotes. This works for both SQL and
- * psql internal. Currently disabled because it is reported not to
- * cooperate with certain versions of readline.
+ * Quote a filename according to SQL rules, returning a malloc'd string.
+ * completion_charp must point to escape character or '\0', as per
+ * comments for complete_from_files().
  */
 static char *
-quote_file_name(char *text, int match_type, char *quote_pointer)
+quote_file_name(char *fname, int match_type, char *quote_pointer)
 {
     char       *s;
-    size_t        length;
+    struct stat statbuf;

-    (void) quote_pointer;        /* not used */
+    /* We always quote (so quote_if_needed's API is overkill) */
+    s = quote_if_needed(fname, " \t\r\n\"`",
+                        '\'', *completion_charp,
+                        true,
+                        pset.encoding);
+
+    /*
+     * However, some of the time we have to strip the trailing quote from what
+     * we send back.  The tests on "s" are just paranoia given that we forced
+     * quoting.  Never strip the trailing quote if the user already typed one;
+     * otherwise, suppress the trailing quote if we have multiple/no matches
+     * (because we don't want to add a quote if the input is seemingly
+     * unfinished), or if the input was already quoted (because Readline will
+     * do arguably-buggy things otherwise), or if the file does not exist, or
+     * if it's a directory.
+     */
+    if (s && *s &&
+        completion_last_char != '\'' &&
+        (match_type != SINGLE_MATCH ||
+         (quote_pointer && *quote_pointer == '\'') ||
+         stat(fname, &statbuf) != 0 ||
+         S_ISDIR(statbuf.st_mode)))
+    {
+        char       *send = s + strlen(s) - 1;
+
+        Assert(*send == '\'');
+        *send = '\0';
+    }
+
+    /*
+     * And now we can let Readline do its thing with possibly adding a quote
+     * on its own accord.  (This covers some additional cases beyond those
+     * dealt with above.)
+     */
+    rl_completion_suppress_quote = 0;
+
+    /*
+     * If user typed a leading quote character other than single quote (i.e.,
+     * double quote), zap it, so that we replace it with the correct single
+     * quote.
+     */
+    if (quote_pointer && *quote_pointer != '\'')
+        *quote_pointer = '\0';

-    length = strlen(text) +(match_type == SINGLE_MATCH ? 3 : 2);
-    s = pg_malloc(length);
-    s[0] = '\'';
-    strcpy(s + 1, text);
-    if (match_type == SINGLE_MATCH)
-        s[length - 2] = '\'';
-    s[length - 1] = '\0';
     return s;
 }

+/*
+ * Dequote a filename, if it's quoted.
+ * completion_charp must point to escape character or '\0', as per
+ * comments for complete_from_files().
+ */
 static char *
-dequote_file_name(char *text, char quote_char)
+dequote_file_name(char *fname, int quote_char)
 {
-    char       *s;
-    size_t        length;
+    char       *unquoted_fname;
+
+    /*
+     * If quote_char is set, it's not included in "fname".  We have to add it
+     * or strtokx will not interpret the string correctly (notably, it won't
+     * recognize escapes).
+     */
+    if (quote_char == '\'')
+    {
+        char       *workspace = (char *) pg_malloc(strlen(fname) + 2);

-    if (!quote_char)
-        return pg_strdup(text);
+        workspace[0] = quote_char;
+        strcpy(workspace + 1, fname);
+        unquoted_fname = strtokx(workspace, "", NULL, "'", *completion_charp,
+                                 false, true, pset.encoding);
+        free(workspace);
+    }
+    else
+        unquoted_fname = strtokx(fname, "", NULL, "'", *completion_charp,
+                                 false, true, pset.encoding);

-    length = strlen(text);
-    s = pg_malloc(length - 2 + 1);
-    strlcpy(s, text +1, length - 2 + 1);
+    /* expect a NULL return for the empty string only */
+    if (!unquoted_fname)
+    {
+        Assert(*fname == '\0');
+        unquoted_fname = fname;
+    }

-    return s;
+    /* readline expects a malloc'd result that it is to free */
+    return pg_strdup(unquoted_fname);
 }
-#endif                            /* NOT_USED */
+
+#endif                            /* USE_FILENAME_QUOTING_FUNCTIONS */

 #endif                            /* USE_READLINE */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 050c48b..983d94e 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -488,6 +488,14 @@
 /* Define to 1 if you have the `rl_filename_completion_function' function. */
 #undef HAVE_RL_FILENAME_COMPLETION_FUNCTION

+/* Define to 1 if you have the global variable 'rl_filename_quote_characters'.
+   */
+#undef HAVE_RL_FILENAME_QUOTE_CHARACTERS
+
+/* Define to 1 if you have the global variable 'rl_filename_quoting_function'.
+   */
+#undef HAVE_RL_FILENAME_QUOTING_FUNCTION
+
 /* Define to 1 if you have the `rl_reset_screen_size' function. */
 #undef HAVE_RL_RESET_SCREEN_SIZE

diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index 909bded..979964c 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -333,6 +333,8 @@ sub GenerateFiles
         HAVE_RL_COMPLETION_APPEND_CHARACTER      => undef,
         HAVE_RL_COMPLETION_MATCHES               => undef,
         HAVE_RL_FILENAME_COMPLETION_FUNCTION     => undef,
+        HAVE_RL_FILENAME_QUOTE_CHARACTERS        => undef,
+        HAVE_RL_FILENAME_QUOTING_FUNCTION        => undef,
         HAVE_RL_RESET_SCREEN_SIZE                => undef,
         HAVE_SECURITY_PAM_APPL_H                 => undef,
         HAVE_SETPROCTITLE                        => undef,