Support substitutions for repository/branch names.

This patch adds support for 's///' style substitutions for the
repository/branch names in the match rulesets. Useful when e.g. eliminating
characters not supported in git branch names.

Syntax:

match /...
    repository some_repo
    substitute repository s/pattern/replacement/
    branch some_branch
    substitute branch s/pattern/replacement/
end match

Author: modax

src/ruleparser.cpp

@@ -77,6 +77,48 @@ const QList<Rules::Match> Rules::matchRules() const
     return m_matchRules;
 }
 
+Rules::Match::Substitution Rules::parseSubstitution(const QString &string)
+{
+    if (string.at(0) != 's' || string.length() < 5)
+        return Match::Substitution();
+
+    const QChar sep = string.at(1);
+
+    if (string.at(string.length() - 1) != sep)
+        return Match::Substitution();
+
+    int i = 2, end = 0;
+    Match::Substitution subst;
+
+    // Separator might have been escaped with a backslash
+    while (i > end) {
+        int backslashCount = 0;
+        if ((end = string.indexOf(sep, i)) > -1) {
+            for (i = end - 1; i >= 2; i--) {
+                if (string.at(i) == '\\')
+                    backslashCount++;
+                else
+                    break;
+            }
+        } else {
+            return Match::Substitution(); // error
+        }
+
+        if (backslashCount % 2 != 0) {
+            // Separator was escaped. Search for another one
+            i = end + 1;
+        }
+    }
+
+    // Found the end of the pattern
+    subst.pattern = QRegExp(string.mid(2, end - 2));
+    if (!subst.pattern.isValid())
+        return Match::Substitution(); // error
+    subst.replacement = string.mid(end + 1, string.length() - 1 - end - 1);
+
+    return subst;
+}
+
 void Rules::load()
 {
     load(filename);
@@ -93,7 +135,9 @@ void Rules::load(const QString &filename)
     QRegExp matchLine("match\\s+(.*)", Qt::CaseInsensitive);
     QRegExp matchActionLine("action\\s+(\\w+)", Qt::CaseInsensitive);
     QRegExp matchRepoLine("repository\\s+(\\S+)", Qt::CaseInsensitive);
+    QRegExp matchRepoSubstLine("substitute repository\\s+(.+)$", Qt::CaseInsensitive);
     QRegExp matchBranchLine("branch\\s+(\\S+)", Qt::CaseInsensitive);
+    QRegExp matchBranchSubstLine("substitute branch\\s+(.+)$", Qt::CaseInsensitive);
     QRegExp matchRevLine("(min|max) revision (\\d+)", Qt::CaseInsensitive);
     QRegExp matchAnnotateLine("annotated\\s+(\\S+)", Qt::CaseInsensitive);
     QRegExp matchPrefixLine("prefix\\s+(\\S+)", Qt::CaseInsensitive);
@@ -175,6 +219,22 @@ void Rules::load(const QString &filename)
                 } else if (matchBranchLine.exactMatch(line)) {
                     match.branch = matchBranchLine.cap(1);
                     continue;
+                } else if (matchRepoSubstLine.exactMatch(line)) {
+                    Match::Substitution subst = parseSubstitution(matchRepoSubstLine.cap(1));
+                    if (!subst.isValid()) {
+                        qFatal("Malformed substitution in rules file: line %d: %s",
+                            lineNumber, qPrintable(origLine));
+                    }
+                    match.repo_substs += subst;
+                    continue;
+                } else if (matchBranchSubstLine.exactMatch(line)) {
+                    Match::Substitution subst = parseSubstitution(matchBranchSubstLine.cap(1));
+                    if (!subst.isValid()) {
+                        qFatal("Malformed substitution in rules file: line %d: %s",
+                            lineNumber, qPrintable(origLine));
+                    }
+                    match.branch_substs += subst;
+                    continue;
                 } else if (matchRevLine.exactMatch(line)) {
                     if (matchRevLine.cap(1) == "min")
                         match.minRevision = matchRevLine.cap(2).toInt();

src/ruleparser.h

@@ -57,9 +57,19 @@ class Rules
 
     struct Match : Rule
     {
+        struct Substitution {
+            QRegExp pattern;
+            QString replacement;
+
+            bool isValid() { return !pattern.isEmpty(); }
+            QString& apply(QString &string) { return string.replace(pattern, replacement); }
+        };
+
         QRegExp rx;
         QString repository;
+        QList<Substitution> repo_substs;
         QString branch;
+        QList<Substitution> branch_substs;
         QString prefix;
         int minRevision;
         int maxRevision;
@@ -83,6 +93,7 @@ class Rules
 
     const QList<Repository> repositories() const;
     const QList<Match> matchRules() const;
+    Match::Substitution parseSubstitution(const QString &string);
     void load();
 
 private:

src/svn.cpp

@@ -214,11 +214,17 @@ static void splitPathName(const Rules::Match &rule, const QString &pathName, QSt
     if (repository_p) {
         *repository_p = svnprefix;
         repository_p->replace(rule.rx, rule.repository);
+        foreach (Rules::Match::Substitution subst, rule.repo_substs) {
+            subst.apply(*repository_p);
+        }
     }
 
     if (branch_p) {
         *branch_p = svnprefix;
         branch_p->replace(rule.rx, rule.branch);
+        foreach (Rules::Match::Substitution subst, rule.branch_substs) {
+            subst.apply(*branch_p);
+        }
     }
 
     if (path_p) {