[kdiff3] /: Fix behavior of preprocessor for sigle quotes

[Michael Reeves]

Git commit 311bf4ea4b5b4ee4b3c3b7fd46553cf60b3a45aa by Michael Reeves.
Committed on 09/07/2018 at 03:13.
Pushed by mreeves into branch 'master'.

Fix behavior of preprocessor for sigle quotes

The distinction between single and double quotes is purly a command
shell issue. So silently convert to double quotes.
Also change escaping to QTs non-standard form for double quotes if
contained in single quotes.

BUG: 209885
FIXED-IN: 1.7

M  +0    -2    doc/en/index.docbook
M  +23   -2    src/pdiff.cpp

https://commits.kde.org/kdiff3/311bf4ea4b5b4ee4b3c3b7fd46553cf60b3a45aa

diff --git a/doc/en/index.docbook b/doc/en/index.docbook
index 0437893..5770710 100644
--- a/doc/en/index.docbook
+++ b/doc/en/index.docbook
@@ -1130,8 +1130,6 @@ Note that the following examples assume that the <command>sed</command>-command
 directory in the PATH-environment variable. If this is not the case, you have to specify the full absolute
 path for the command. 
 </para>
-<note><para>Also note that the following examples use the single quotation mark (') which won't work for Windows. 
-On Windows you should use the double quotation marks (") instead.</para></note>
 <para>
 In this context only the <command>sed</command>-substitute-command is used:
 <screen>
diff --git a/src/pdiff.cpp b/src/pdiff.cpp
index 060a246..a19be99 100644
--- a/src/pdiff.cpp
+++ b/src/pdiff.cpp
@@ -2287,11 +2287,32 @@ void KDiff3App::slotNoRelevantChangesDetected()
         //KMessageBox::information( this, "No relevant changes detected", "KDiff3" );
         if(!m_pOptions->m_IrrelevantMergeCmd.isEmpty())
         {
-            QString cmd = m_pOptions->m_IrrelevantMergeCmd + " \"" + m_sd1.getAliasName() + "\" \"" + m_sd2.getAliasName() + "\" \"" + m_sd3.getAliasName();
+            QString cmd = m_pOptions->m_IrrelevantMergeCmd;
+            /*
+                QProcess doesn't check for single quotes and uses non-standard escaping syntax for double quotes.
+                    The distinction between single and double quotes is purly a command shell issue. So
+                    Silently convert quotes to what QProcess understands. Also convert '\"' to '"""'
+            */
+            //arg and arg1 can never both match but qt's pcre2 engine insists on unique naming anyway
+            const QRegularExpression argRe("(?<!\\\\)\"(?<arg>(?:[^\"]|(?<=\\\\)\")*)(?<!\\\\)\"|'(?<arg1>[^']*)'");
+            QRegularExpressionMatchIterator i = argRe.globalMatch(cmd);
+            QRegularExpressionMatch match;
+            QStringList args;
+
+            while(i.hasNext())
+            {
+                match = i.next();
+                args += match.captured("arg").replace("\\\"", "\"\"\"").replace("\\\\", "\\")
+                    + match.captured("arg1");
+            }
+            args += m_sd1.getAliasName();
+            args += m_sd2.getAliasName();
+            args += m_sd3.getAliasName();
+            cmd = cmd.left(cmd.indexOf('"')).trimmed();
+
             QProcess process;
             process.start(cmd);
             process.waitForFinished(-1);
-            //::system( cmd.local8Bit() );
         }
     }
 }