fix handling math check in math alias envs

src/syntaxcheck.cpp

@@ -442,8 +442,18 @@ bool SyntaxCheck::checkCommand(const QString &cmd, const StackEnvironment &envs)
     bool textOrMathEnvUsed=false;
     for (int i = envs.size()-1; i > -1; --i) {
 		Environment env = envs.at(i);
-        if(textOrMathEnvUsed &&(env.name=="math" || env.name=="text" )){
-            continue; // only the lowest text/math is valid as they can be used alternately
+        if(textOrMathEnvUsed){
+            if(env.name=="math" || env.name=="text" ) continue; // only the lowest text/math is valid as they can be used alternately
+            // look also for alias envs!
+            QStringList altEnvs = ltxCommands->environmentAliases.values(env.name);
+            bool skip=false;
+            foreach (const QString &altEnv, altEnvs) {
+                if (altEnv=="math" || altEnv=="text" ){
+                    skip=true;
+                    break;
+                }
+            }
+            if(skip) continue; // only the lowest text/math is valid as they can be used alternately
         }
 		if (ltxCommands->possibleCommands.contains(env.name) && ltxCommands->possibleCommands.value(env.name).contains(cmd))
 			return true;

src/tests/syntaxcheck_t.cpp

@@ -414,7 +414,10 @@ void SyntaxCheckTest::checkAllowedMath_data(){
              <<"$\\textit{$ {\\alpha}$}$"<<false;
      QTest::newRow("nested math in text in math and extra braces (underscore)")
              <<"$\\textit{$ {a_b}$}$"<<false;
-
+     QTest::newRow("handle math aliases correctly")
+         <<"\\usepackage{amsmath}\n\\begin{align}\n\\alpha\n\\end{align}"<<false;
+     QTest::newRow("handle math aliases correctly, force error")
+         <<"\\usepackage{amsmath}\n\\begin{align}\n\\text{\\alpha}\n\\end{align}"<<true;
 }
 
 void SyntaxCheckTest::checkAllowedMath(){