fnmatch: use the system one if available

If configure detects fnmatch to be available, use that instead of our
custom one for FTP wildcard pattern matching. For standard compliance,
to reduce our footprint and to use already well tested and well
exercised code.

A POSIX fnmatch behaves slightly different than the internal function
for a few test patterns currently and the macOS one yet slightly
different. Test case 1307 is adjusted for these differences.

Closes #2626

3 files changed, 119 insertions, 19 deletions

diff --git a/configure.ac b/configure.ac
index 9c4e697de..fa5dc84f5 100755
--- a/configure.ac
+++ b/configure.ac
@@ -3623,7 +3623,8 @@ AC_CHECK_DECLS([getpwuid_r], [], [AC_DEFINE(HAVE_DECL_GETPWUID_R_MISSING, 1, "Se
           #include <sys/types.h>]])
 
 
-AC_CHECK_FUNCS([geteuid \
+AC_CHECK_FUNCS([fnmatch \
+  geteuid \
   getpass_r \
   getppid \
   getpwuid \
diff --git a/lib/curl_fnmatch.c b/lib/curl_fnmatch.c
index bd4e61f4e..e8aff6761 100644
--- a/lib/curl_fnmatch.c
+++ b/lib/curl_fnmatch.c
@@ -30,6 +30,17 @@
 /* The last #include file should be: */
 #include "memdebug.h"
 
+#ifndef HAVE_FNMATCH
+
+/*
+ * TODO:
+ *
+ * Make this function match POSIX. Test 1307 includes a set of test patterns
+ * that returns different results with a POSIX fnmatch() than with this
+ * implemenation and this is considered a bug where POSIX is the guiding
+ * light.
+ */
+
 #define CURLFNM_CHARSET_LEN (sizeof(char) * 256)
 #define CURLFNM_CHSET_SIZE (CURLFNM_CHARSET_LEN + 15)
 
@@ -357,3 +368,29 @@ int Curl_fnmatch(void *ptr, const char *pattern, const char *string)
   }
   return loop((unsigned char *)pattern, (unsigned char *)string, 2);
 }
+#else
+#include <fnmatch.h>
+/*
+ * @unittest: 1307
+ */
+int Curl_fnmatch(void *ptr, const char *pattern, const char *string)
+{
+  int rc;
+  (void)ptr; /* the argument is specified by the curl_fnmatch_callback
+                prototype, but not used by Curl_fnmatch() */
+  if(!pattern || !string) {
+    return CURL_FNMATCH_FAIL;
+  }
+  rc = fnmatch(pattern, string, 0);
+  switch(rc) {
+  case 0:
+    return CURL_FNMATCH_MATCH;
+  case FNM_NOMATCH:
+    return CURL_FNMATCH_NOMATCH;
+  default:
+    return CURL_FNMATCH_FAIL;
+  }
+  /* not reached */
+}
+
+#endif
diff --git a/tests/unit/unit1307.c b/tests/unit/unit1307.c
index fe16ed324..22afa4bf2 100644
--- a/tests/unit/unit1307.c
+++ b/tests/unit/unit1307.c
@@ -23,13 +23,31 @@
 
 #include "curl_fnmatch.h"
 
+/*
+   CURL_FNMATCH_MATCH    0
+   CURL_FNMATCH_NOMATCH  1
+   CURL_FNMATCH_FAIL     2
+ */
+
 #define MATCH   CURL_FNMATCH_MATCH
 #define NOMATCH CURL_FNMATCH_NOMATCH
 
+#define LINUX_DIFFER 0x80
+#define LINUX_SHIFT 8
+#define LINUX_MATCH ((CURL_FNMATCH_MATCH << LINUX_SHIFT) | LINUX_DIFFER)
+#define LINUX_NOMATCH ((CURL_FNMATCH_NOMATCH << LINUX_SHIFT) | LINUX_DIFFER)
+#define LINUX_FAIL ((CURL_FNMATCH_FAIL << LINUX_SHIFT) | LINUX_DIFFER)
+
+#define MAC_DIFFER 0x40
+#define MAC_SHIFT 16
+#define MAC_MATCH ((CURL_FNMATCH_MATCH << MAC_SHIFT) | MAC_DIFFER)
+#define MAC_NOMATCH ((CURL_FNMATCH_NOMATCH << MAC_SHIFT) | MAC_DIFFER)
+#define MAC_FAIL ((CURL_FNMATCH_FAIL << MAC_SHIFT) | MAC_DIFFER)
+
 struct testcase {
   const char *pattern;
   const char *string;
-  int  result;
+  int result;
 };
 
 static const struct testcase tests[] = {
@@ -40,11 +58,11 @@ static const struct testcase tests[] = {
    "[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[["
    "[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[["
    "[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[",
-   NOMATCH},
+   NOMATCH|MAC_FAIL},
 
   { "\\[",                      "[",                      MATCH },
-  { "[",                        "[",                      NOMATCH },
-  { "[]",                       "[]",                     NOMATCH },
+  { "[",                        "[",             NOMATCH|LINUX_MATCH|MAC_FAIL},
+  { "[]",                       "[]",            NOMATCH|LINUX_MATCH|MAC_FAIL},
   { "[][]",                     "[",                      MATCH },
   { "[][]",                     "]",                      MATCH },
   { "[[]",                      "[",                      MATCH },
@@ -86,7 +104,7 @@ static const struct testcase tests[] = {
   { "[][?*-]",                  "*",                      MATCH },
   { "[][?*-]",                  "-",                      MATCH },
   { "[]?*-]",                   "-",                      MATCH },
-  { "[\xFF]",                   "\xFF",                   MATCH },
+  { "[\xFF]",                   "\xFF", MATCH|LINUX_FAIL|MAC_FAIL},
   { "?/b/c",                    "a/b/c",                  MATCH },
   { "^_{}~",                    "^_{}~",                  MATCH },
   { "!#%+,-./01234567889",      "!#%+,-./01234567889",    MATCH },
@@ -108,9 +126,9 @@ static const struct testcase tests[] = {
   { "*[^a].t?t",                "ba.txt",                 NOMATCH },
   { "*[^a].t?t",                "ab.txt",                 MATCH },
   { "*[^a]",                    "",                       NOMATCH },
-  { "[!\xFF]",                  "",                       NOMATCH },
-  { "[!\xFF]",                  "\xFF",                   NOMATCH },
-  { "[!\xFF]",                  "a",                      MATCH },
+  { "[!\xFF]",                  "",             NOMATCH|LINUX_FAIL},
+  { "[!\xFF]",                  "\xFF",  NOMATCH|LINUX_FAIL|MAC_FAIL},
+  { "[!\xFF]",                  "a",      MATCH|LINUX_FAIL|MAC_FAIL},
   { "[!?*[]",                   "?",                      NOMATCH },
   { "[!!]",                     "!",                      NOMATCH },
   { "[!!]",                     "x",                      MATCH },
@@ -142,8 +160,8 @@ static const struct testcase tests[] = {
   { "[^[:blank:]]",             "\t",                     NOMATCH },
   { "[^[:print:]]",             "\10",                    MATCH },
   { "[[:lower:]][[:lower:]]",   "ll",                     MATCH },
-  { "[[:foo:]]",                "bar",                    NOMATCH },
-  { "[[:foo:]]",                "f]",                     MATCH },
+  { "[[:foo:]]",                "bar",                    NOMATCH|MAC_FAIL},
+  { "[[:foo:]]",                "f]",         MATCH|LINUX_NOMATCH|MAC_FAIL},
 
   { "Curl[[:blank:]];-)",       "Curl ;-)",               MATCH },
   { "*[[:blank:]]*",            " ",                      MATCH },
@@ -181,7 +199,7 @@ static const struct testcase tests[] = {
   { "x",                        "",                       NOMATCH },
 
   /* backslash */
-  { "\\",                       "\\",                     MATCH },
+  { "\\",                       "\\",                     MATCH|LINUX_NOMATCH},
   { "\\\\",                     "\\",                     MATCH },
   { "\\\\",                     "\\\\",                   NOMATCH },
   { "\\?",                      "?",                      MATCH },
@@ -214,11 +232,11 @@ static const struct testcase tests[] = {
 
   { "Lindmätarv",               "Lindmätarv",             MATCH },
 
-  { "",                         "",                       MATCH },
+  { "",                         "",                       MATCH},
   {"**]*[*[\x13]**[*\x13)]*]*[**[*\x13~r-]*]**[.*]*[\xe3\xe3\xe3\xe3\xe3\xe3"
    "\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3\xe3"
    "\xe3\xe3\xe3\xe3\xe3*[\x13]**[*\x13)]*]*[*[\x13]*[~r]*]*\xba\x13\xa6~b-]*",
-                                "a",                      NOMATCH }
+                                "a",                      NOMATCH|LINUX_FAIL}
 };
 
 static CURLcode unit_setup(void)
@@ -230,19 +248,63 @@ static void unit_stop(void)
 {
 }
 
-UNITTEST_START
+static const char *ret2name(int i)
+{
+  switch(i) {
+  case 0:
+    return "MATCH";
+  case 1:
+    return "NOMATCH";
+  case 2:
+    return "FAIL";
+  default:
+    return "unknown";
+  }
+  /* not reached */
+}
 
+enum system {
+  SYSTEM_CUSTOM,
+  SYSTEM_LINUX,
+  SYSTEM_MACOS
+};
+
+UNITTEST_START
+{
   int testnum = sizeof(tests) / sizeof(struct testcase);
   int i, rc;
+  enum system machine;
+
+#ifdef HAVE_FNMATCH
+  if(strstr(OS, "apple") || strstr(OS, "darwin")) {
+    machine = SYSTEM_MACOS;
+  }
+  else
+    machine = SYSTEM_LINUX;
+  printf("Tested with system fnmatch(), %s-style\n",
+         machine == SYSTEM_LINUX ? "linux" : "mac");
+#else
+  printf("Tested with custom fnmatch()\n");
+  machine = SYSTEM_CUSTOM;
+#endif
 
   for(i = 0; i < testnum; i++) {
+    int result = tests[i].result;
     rc = Curl_fnmatch(NULL, tests[i].pattern, tests[i].string);
-    if(rc != tests[i].result) {
-      printf("Curl_fnmatch(\"%s\", \"%s\") should return %d (returns %d)"
+    if(result & (LINUX_DIFFER|MAC_DIFFER)) {
+      if((result & LINUX_DIFFER) && (machine == SYSTEM_LINUX))
+        result >>= LINUX_SHIFT;
+      else if((result & MAC_DIFFER) && (machine == SYSTEM_MACOS))
+        result >>= MAC_SHIFT;
+      result &= 0x03; /* filter off all high bits */
+    }
+    if(rc != result) {
+      printf("Curl_fnmatch(\"%s\", \"%s\") should return %s (returns %s)"
              " [%d]\n",
-             tests[i].pattern, tests[i].string, tests[i].result, rc, i);
+             tests[i].pattern, tests[i].string, ret2name(result),
+             ret2name(rc), i);
       fail("pattern mismatch");
     }
   }
-
+}
 UNITTEST_STOP