core: New API gpgrt_cmp_version

* src/gpg-error.h.in: New API gpgrt_cmp_version.
* src/visibility.c (gpgrt_cmp_version): New wrapper.
* src/version.c (parse_version_string): Revamped.
(do_cmp_version): New.
(_gpgrt_cmp_version): New.
(_gpg_error_check_version): Re-implemented using the new func.
* tests/t-version.c: Include t-common.h.
(t_gpgrt_cmp_version): New test.
(main): Run new test.  Change test for new version number to require a
2 level number.
--

We have implementations of very similar functions in all out libs.
Thus it makes sense to provide a generic version.  This version is
actually derived from the ftp-indexer.c we use for the gnupg
website (see the gnupg-doc repo).

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 152 insertions, 27 deletions

diff --git a/src/version.c b/src/version.c
index 94b75af..ac2f057 100644
--- a/src/version.c
+++ b/src/version.c
@@ -47,6 +47,10 @@ cright_blurb (void)
 }
 
 
+/* This function parses the first portion of the version number S and
+ * stores it at NUMBER.  On success, this function returns a pointer
+ * into S starting with the first character, which is not part of the
+ * initial number portion; on failure, NULL is returned.  */
 static const char*
 parse_version_number (const char *s, int *number)
 {
@@ -64,45 +68,161 @@ parse_version_number (const char *s, int *number)
 }
 
 
+/* This function breaks up the complete string-representation of the
+ * version number S, which is of the following struture: <major
+ * number>.<minor number>.<micro number><patch level>.  The major,
+ * minor and micro number components will be stored in *MAJOR, *MINOR
+ * and *MICRO.  If MINOR or MICRO is NULL the version number is
+ * assumed to have just 1 respective 2 parts.
+ *
+ * On success, the last component, the patch level, will be returned;
+ * in failure, NULL will be returned.  */
 static const char *
-parse_version_string (const char *s, int *major, int *minor)
+parse_version_string (const char *s, int *major, int *minor, int *micro)
 {
   s = parse_version_number (s, major);
-  if (!s || *s != '.')
-    return NULL;
-  s++;
-  s = parse_version_number (s, minor);
   if (!s)
     return NULL;
-  return s;  /* Patchlevel.  */
+  if (!minor)
+    {
+      if (*s == '.')
+        s++;
+    }
+  else
+    {
+      if (*s != '.')
+        return NULL;
+      s++;
+      s = parse_version_number (s, minor);
+      if (!s)
+        return NULL;
+      if (!micro)
+        {
+          if (*s == '.')
+            s++;
+        }
+      else
+        {
+          if (*s != '.')
+            return NULL;
+          s++;
+          s = parse_version_number (s, micro);
+          if (!s)
+            return NULL;
+        }
+    }
+  return s; /* patchlevel */
 }
 
 
-static const char *
-compare_versions (const char *my_version, const char *req_version)
+/* Helper for _gpgrt_cmp_version.  */
+static int
+do_cmp_version (const char *a, const char *b, int level)
 {
-  int my_major, my_minor;
-  int rq_major, rq_minor;
-  const char *my_plvl, *rq_plvl;
+  int a_major, a_minor, a_micro;
+  int b_major, b_minor, b_micro;
+  const char *a_plvl, *b_plvl;
+  int r;
+  int ignore_plvl;
+  int positive, negative;
+
+  if (level < 0)
+    {
+      positive = -1;
+      negative = 1;
+      level = 0 - level;
+    }
+  else
+    {
+      positive = 1;
+      negative = -1;
+    }
+  if ((ignore_plvl = (level > 9)))
+    level %= 10;
+
+  a_major = a_minor = a_micro = 0;
+  a_plvl = parse_version_string (a, &a_major,
+                                 level > 1? &a_minor : NULL,
+                                 level > 2? &a_micro : NULL);
+  if (!a_plvl)
+    a_major = a_minor = a_micro = 0; /* Error.  */
+
+  b_major = b_minor = b_micro = 0;
+  b_plvl = parse_version_string (b, &b_major,
+                                 level > 1? &b_minor : NULL,
+                                 level > 2? &b_micro : NULL);
+  if (!b_plvl)
+    b_major = b_minor = b_micro = 0;
+
+  if (!ignore_plvl)
+    {
+      if (!a_plvl && !b_plvl)
+        return negative;  /* Put invalid strings at the end.  */
+      if (a_plvl && !b_plvl)
+        return positive;
+      if (!a_plvl && b_plvl)
+        return negative;
+    }
 
-  if (!req_version)
-    return my_version;
-  if (!my_version)
-    return NULL;
+  if (a_major > b_major)
+    return positive;
+  if (a_major < b_major)
+    return negative;
+
+  if (a_minor > b_minor)
+    return positive;
+  if (a_minor < b_minor)
+    return negative;
+
+  if (a_micro > b_micro)
+    return positive;
+  if (a_micro < b_micro)
+    return negative;
 
-  my_plvl = parse_version_string (my_version, &my_major, &my_minor);
-  if (!my_plvl)
-    return NULL;	/* Very strange: our own version is bogus.  */
-  rq_plvl = parse_version_string(req_version, &rq_major, &rq_minor);
-  if (!rq_plvl)
-    return NULL;	/* Requested version string is invalid.  */
+  if (ignore_plvl)
+    return 0;
 
-  if (my_major > rq_major
-      || (my_major == rq_major && my_minor >= rq_minor))
+  for (; *a_plvl && *b_plvl; a_plvl++, b_plvl++)
     {
-      return my_version;
-    }
-  return NULL;
+      if (*a_plvl == '.' && *b_plvl == '.')
+        {
+          r = strcmp (a_plvl, b_plvl);
+          if (!r)
+            return 0;
+          else if ( r > 0 )
+            return positive;
+          else
+            return negative;
+        }
+      else if (*a_plvl == '.')
+        return negative; /* B is larger. */
+      else if (*b_plvl == '.')
+        return positive; /* A is larger. */
+      else if (*a_plvl != *b_plvl)
+        break;
+        }
+  if (*a_plvl == *b_plvl)
+    return 0;
+  else if ((*(signed char *)a_plvl - *(signed char *)b_plvl) > 0)
+    return positive;
+  else
+    return negative;
+}
+
+
+/* Compare function for version strings.  The return value is
+ * like strcmp().  LEVEL may be
+ *   0 - reserved
+ *   1 - format is "<major><patchlevel>".
+ *   2 - format is "<major>.<minor><patchlevel>".
+ *   3 - format is "<major>.<minor>.<micro><patchlevel>".
+ * To ignore the patchlevel in the comparison add 10 to LEVEL.  To get
+ * a reverse sorting order use a negative number.
+ */
+int
+_gpgrt_cmp_version (const char *a, const char *b, int level)
+{
+  return do_cmp_version (a, b, level);
 }
 
 
@@ -115,7 +235,12 @@ compare_versions (const char *my_version, const char *req_version)
 const char *
 _gpg_error_check_version (const char *req_version)
 {
+  const char *my_version = PACKAGE_VERSION;
+
   if (req_version && req_version[0] == 1 && req_version[1] == 1)
     return cright_blurb ();
-  return compare_versions (PACKAGE_VERSION, req_version);
+  if (!req_version)
+    return my_version;
+  return _gpgrt_cmp_version
+    (my_version, req_version, 12) >= 0 ? my_version : NULL;
 }