Allow $repo expansion in 'Server' config lines

Small change (addition of a 'strreplace' function) which replaces
any $repo tokens found in a server line with the name of the repo
or section being processed.

While this is more simplistic than suggestions on flyspray, it works
and I think it is cleaner.  Merits can be discussed further.

Ref: FS#6389

Signed-off-by: Aaron Griffin <aaronmgriffin@gmail.com>

lib/libalpm/alpm.c

@@ -224,7 +224,7 @@ int alpm_db_setserver(pmdb_t *db, const char *url)
 		}
 		db->servers = alpm_list_add(db->servers, server);
 		_alpm_log(PM_LOG_DEBUG, _("adding new server to database '%s': protocol '%s', server '%s', path '%s'"),
-				db->treename, server->s_url->scheme, server->s_url->host, server->s_url->doc);
+							db->treename, server->s_url->scheme, server->s_url->host, server->s_url->doc);
 	} else {
 		FREELIST(db->servers);
 		_alpm_log(PM_LOG_DEBUG, _("serverlist flushed for '%s'"), db->treename);
@@ -467,8 +467,8 @@ int alpm_pkg_checksha1sum(pmpkg_t *pkg)
 	ASSERT(pkg->data != handle->db_local, RET_ERR(PM_ERR_PKG_INVALID, -1));
 
 	snprintf(path, PATH_MAX, "%s%s/%s-%s" PM_EXT_PKG,
-	                handle->root, handle->cachedir,
+					 handle->root, handle->cachedir,
-	                alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg));
+					 alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg));
 
 	sha1sum = _alpm_SHAFile(path);
 	if(sha1sum == NULL) {
@@ -511,8 +511,8 @@ int alpm_pkg_checkmd5sum(pmpkg_t *pkg)
 	ASSERT(pkg->data != handle->db_local, RET_ERR(PM_ERR_PKG_INVALID, -1));
 
 	snprintf(path, PATH_MAX, "%s%s/%s-%s" PM_EXT_PKG,
-	                handle->root, handle->cachedir,
+					 handle->root, handle->cachedir,
-									alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg));
+					 alpm_pkg_get_name(pkg), alpm_pkg_get_version(pkg));
 
 	md5sum = _alpm_MDFile(path);
 	if(md5sum == NULL) {
@@ -545,7 +545,7 @@ int alpm_pkg_checkmd5sum(pmpkg_t *pkg)
  */
 int SYMEXPORT alpm_pkg_vercmp(const char *ver1, const char *ver2)
 {
- 	ALPM_LOG_FUNC;
+	ALPM_LOG_FUNC;
 
 	return(_alpm_versioncmp(ver1, ver2));
 }
@@ -636,8 +636,8 @@ alpm_list_t SYMEXPORT *alpm_db_search(pmdb_t *db, alpm_list_t* needles)
  * @return 0 on success, -1 on error (pm_errno is set accordingly)
  */
 int SYMEXPORT alpm_trans_init(pmtranstype_t type, pmtransflag_t flags,
-                    alpm_trans_cb_event event, alpm_trans_cb_conv conv,
+															alpm_trans_cb_event event, alpm_trans_cb_conv conv,
-                    alpm_trans_cb_progress progress)
+															alpm_trans_cb_progress progress)
 {
 	char path[PATH_MAX];
 
@@ -1059,11 +1059,15 @@ int SYMEXPORT alpm_parse_config(char *file, alpm_cb_db_register callback, const
 					}
 				} else {
 					if(strcmp(origkey, "Server") == 0 || strcmp(key, "SERVER") == 0) {
-						/* add to the list */
+						/* let's attempt a replacement for the current repo */
-						if(alpm_db_setserver(db, ptr) != 0) {
+						char *server = _alpm_strreplace(ptr, "$repo", section);
+
+						if(alpm_db_setserver(db, server) != 0) {
 							/* pm_errno is set by alpm_db_setserver */
 							return(-1);
 						}
+
+						free(server);
 					} else {
 						RET_ERR(PM_ERR_CONF_BAD_SYNTAX, -1);
 					}

lib/libalpm/util.c

@@ -161,7 +161,7 @@ int _alpm_copyfile(const char *src, const char *dest)
 }
 
 /* Convert a string to uppercase
- */
+*/
 char *_alpm_strtoupper(char *str)
 {
 	char *ptr = str;
@@ -174,7 +174,7 @@ char *_alpm_strtoupper(char *str)
 }
 
 /* Trim whitespace and newlines from a string
- */
+*/
 char *_alpm_strtrim(char *str)
 {
 	char *pch = str;
@@ -205,8 +205,53 @@ char *_alpm_strtrim(char *str)
 	return(str);
 }
 
+/* Helper function for _alpm_strreplace */
+static void _strnadd(char **str, const char *append, unsigned int count)
+{
+	if(*str) {
+		*str = realloc(*str, strlen(*str) + count + 1);
+	} else {
+		*str = calloc(sizeof(char), count + 1);
+	}
+
+	strncat(*str, append, count);
+}
+
+/* Replace all occurances of 'needle' with 'replace' in 'str', returning
+ * a new string (must be free'd) */
+char *_alpm_strreplace(const char *str, const char *needle, const char *replace)
+{
+	const char *p, *q;
+	p = q = str;
+
+	char *newstr = NULL;
+	unsigned int needlesz = strlen(needle),
+							 replacesz = strlen(replace);
+
+	while (1) {
+		q = strstr(p, needle);
+		if(!q) { /* not found */ 
+			if(*p) {
+				/* add the rest of 'p' */
+				_strnadd(&newstr, p, strlen(p));
+			}
+			break;
+		} else { /* found match */
+			if(q > p){
+				/* add chars between this occurance and last occurance, if any */
+				_strnadd(&newstr, p, q - p);
+			}
+			_strnadd(&newstr, replace, replacesz);
+			p = q + needlesz;
+		}
+	}
+
+	return newstr;
+}
+
+
 /* Create a lock file
- */
+*/
 int _alpm_lckmk(const char *file)
 {
 	int fd, count = 0;
@@ -234,7 +279,7 @@ int _alpm_lckmk(const char *file)
 }
 
 /* Remove a lock file
- */
+*/
 int _alpm_lckrm(const char *file)
 {
 	if(unlink(file) == -1 && errno != ENOENT) {
@@ -244,7 +289,7 @@ int _alpm_lckrm(const char *file)
 }
 
 /* Compression functions
- */
+*/
 
 int _alpm_unpack(const char *archive, const char *prefix, const char *fn)
 {
@@ -252,8 +297,8 @@ int _alpm_unpack(const char *archive, const char *prefix, const char *fn)
 	struct archive_entry *entry;
 	char expath[PATH_MAX];
 	const int archive_flags = ARCHIVE_EXTRACT_OWNER |
-	                          ARCHIVE_EXTRACT_PERM |
+		ARCHIVE_EXTRACT_PERM |
-	                          ARCHIVE_EXTRACT_TIME;
+		ARCHIVE_EXTRACT_TIME;
 
 	ALPM_LOG_FUNC;
 
@@ -278,7 +323,7 @@ int _alpm_unpack(const char *archive, const char *prefix, const char *fn)
 		archive_entry_set_pathname(entry, expath);
 		if(archive_read_extract(_archive, entry, archive_flags) != ARCHIVE_OK) {
 			_alpm_log(PM_LOG_ERROR, _("could not extract %s: %s\n"), archive_entry_pathname(entry), archive_error_string(_archive));
-			 return(1);
+			return(1);
 		}
 
 		if(fn) {
@@ -349,8 +394,8 @@ int _alpm_logaction(unsigned short usesyslog, FILE *f, const char *str)
 
 		/* Use ISO-8601 date format */
 		fprintf(f, "[%04d-%02d-%02d %02d:%02d] %s\n",
-		        tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
+						tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
-		        tm->tm_hour, tm->tm_min, str);
+						tm->tm_hour, tm->tm_min, str);
 
 		fflush(f);
 	}

lib/libalpm/util.h

@@ -48,6 +48,7 @@ int _alpm_makepath(const char *path);
 int _alpm_copyfile(const char *src, const char *dest);
 char *_alpm_strtoupper(char *str);
 char *_alpm_strtrim(char *str);
+char *_alpm_strreplace(const char *str, const char *needle, const char *replace);
 int _alpm_lckmk(const char *file);
 int _alpm_lckrm(const char *file);
 int _alpm_unpack(const char *archive, const char *prefix, const char *fn);