diff --git a/src/isql/extract.epp b/src/isql/extract.epp
index cc0ba7a7a5..69c4048030 100644
--- a/src/isql/extract.epp
+++ b/src/isql/extract.epp
@@ -494,7 +494,7 @@ int EXTRACT_list_table(const SCHAR* relation_name,
 		if (!RFR.RDB$DEFAULT_SOURCE.NULL)
 		{
 			isqlGlob.printf(" ");
-			SHOW_print_metadata_text_blob (isqlGlob.Out, &RFR.RDB$DEFAULT_SOURCE);
+			SHOW_print_metadata_text_blob(isqlGlob.Out, &RFR.RDB$DEFAULT_SOURCE, false, true);
 		}
 
 		if (!RFR.RDB$GENERATOR_NAME.NULL)
@@ -801,7 +801,7 @@ static void get_procedure_args(const char* proc_name)
 					if (!prm_default_source_null)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source, false, true);
 					}
 				}
 			}
@@ -852,12 +852,12 @@ static void get_procedure_args(const char* proc_name)
 					if (!prm_default_source_null)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source, false, true);
 					}
 					else if (!FLD.RDB$DEFAULT_SOURCE.NULL)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE, false, true);
 					}
 				}
 			}
@@ -1020,7 +1020,7 @@ static void get_function_args_ods12(const char* func_name, USHORT out_arg)
 					if (!prm_default_source_null)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source, false, true);
 					}
 				}
 			}
@@ -1072,12 +1072,12 @@ static void get_function_args_ods12(const char* func_name, USHORT out_arg)
 					if (!prm_default_source_null)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &prm_default_source, false, true);
 					}
 					else if (!FLD.RDB$DEFAULT_SOURCE.NULL)
 					{
 						isqlGlob.printf(" ");
-						SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE);
+						SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE, false, true);
 					}
 				}
 			}
@@ -2262,7 +2262,7 @@ static void list_domain_table(const SCHAR* table_name, SSHORT default_char_set_i
 		if (!FLD.RDB$DEFAULT_SOURCE.NULL)
 		{
 			isqlGlob.printf("%s%s ", NEWLINE, TAB_AS_SPACES);
-			SHOW_print_metadata_text_blob (isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE);
+			SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE, false, true);
 		}
 		if (!FLD.RDB$VALIDATION_SOURCE.NULL)
 		{
@@ -2384,7 +2384,7 @@ static void list_domains(SSHORT default_char_set_id)
 		if (!FLD.RDB$DEFAULT_SOURCE.NULL)
 		{
 			isqlGlob.printf("%s%s ", NEWLINE, TAB_AS_SPACES);
-			SHOW_print_metadata_text_blob (isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE);
+			SHOW_print_metadata_text_blob(isqlGlob.Out, &FLD.RDB$DEFAULT_SOURCE, false, true);
 		}
 		// Validation moved to listDomainConstraints().
 		if (FLD.RDB$NULL_FLAG == 1)
@@ -3270,7 +3270,7 @@ static void list_indexes()
 		{
 			isqlGlob.printf(" COMPUTED BY ");
 			if (!IDX.RDB$EXPRESSION_SOURCE.NULL)
-				SHOW_print_metadata_text_blob (isqlGlob.Out, &IDX.RDB$EXPRESSION_SOURCE);
+				SHOW_print_metadata_text_blob(isqlGlob.Out, &IDX.RDB$EXPRESSION_SOURCE, false, true);
 			isqlGlob.printf("%s%s", isqlGlob.global_Term, NEWLINE);
 		}
 		else if (ISQL_get_index_segments (collist, sizeof(collist), IDX.RDB$INDEX_NAME, true))
diff --git a/src/isql/isql.epp b/src/isql/isql.epp
index 4b4db43596..4d46b1171a 100644
--- a/src/isql/isql.epp
+++ b/src/isql/isql.epp
@@ -575,7 +575,7 @@ static bool M_Transaction()
 {
 	if (DB && !M__trans && setValues.KeepTranParams)
 	{
-		M__trans = DB->execute(fbStatus, NULL, 
+		M__trans = DB->execute(fbStatus, NULL,
 							   TranParams->length(), TranParams->c_str(),
 							   isqlGlob.SQL_dialect, NULL, NULL, NULL, NULL);
 
@@ -1390,6 +1390,123 @@ processing_state ISQL_fill_var(IsqlVar* var,
 }
 
 
+// Check if statement ends with single-line comment.
+bool ISQL_statement_ends_in_comment(const char* statement)
+{
+	const char* const statementStart = statement;
+	const char* commentStart = NULL;
+	const char* commentEnd = NULL;
+	const char* altQuoteStart = NULL;
+	char altQuoteChar = '\0';
+
+	enum
+	{
+		normal,
+		in_single_line_comment,
+		in_block_comment,
+		in_single_quoted_string,
+		in_double_quoted_string
+	} state = normal;
+
+	while (char c = *statement++)
+	{
+		char lastChar = statement - 1 == statementStart ? '\0' : statement[-2];
+
+		switch (c)
+		{
+			case '\n':
+				if (state == in_single_line_comment)
+					state = normal;
+				break;
+
+			case '-':
+				// Could this the be start of a single-line comment.
+				if (state == normal && lastChar == '-')
+					state = in_single_line_comment;
+				break;
+
+			case '*':
+				// Could this the be start of a comment. We can only look back, not forward.
+				// Ignore possibilities of a comment beginning inside quoted strings.
+				if (state == normal && lastChar == '/' && statement - commentEnd > 3)
+				{
+					state = in_block_comment;
+					commentStart = statement - 2;
+				}
+				break;
+
+			case '/':
+				// Perhaps this is the end of a comment.
+				// Ignore possibilities of a comment ending inside quoted strings.
+				// Ignore things like /*/ since it isn't a block comment; only the start of it. Or end.
+				if (state == in_block_comment && lastChar == '*' && statement - commentStart > 3)
+				{
+					state = normal;
+					commentEnd = statement - 2;	// mark start of non-comment to track this: /**/*
+				}
+				break;
+
+			case SINGLE_QUOTE:
+				switch (state)
+				{
+					case normal:
+						if (lastChar == 'q' || lastChar == 'Q')
+						{
+							altQuoteStart = statement - 2;
+
+							if (!(altQuoteChar = *statement++))
+								return false;
+
+							switch (altQuoteChar)
+							{
+								case '{':
+									altQuoteChar = '}';
+									break;
+								case '(':
+									altQuoteChar = ')';
+									break;
+								case '[':
+									altQuoteChar = ']';
+									break;
+								case '<':
+									altQuoteChar = '>';
+									break;
+							}
+						}
+						else
+							altQuoteChar = '\0';
+
+						state = in_single_quoted_string;
+						break;
+
+					case in_single_quoted_string:
+						if (!altQuoteChar || lastChar == altQuoteChar)
+							state = normal;
+						break;
+				}
+				break;
+
+			case DBL_QUOTE:
+				switch (state)
+				{
+					case normal:
+						state = in_double_quoted_string;
+						break;
+					case in_double_quoted_string:
+						state = normal;
+						break;
+				}
+				break;
+
+			default:
+				break;
+		}
+	}
+
+	return state == in_single_line_comment;
+}
+
+
 void ISQL_get_default_source(const TEXT* rel_name,
 							 TEXT* field_name,
 							 ISC_QUAD* blob_id)
@@ -1951,6 +2068,7 @@ void ISQL_print_validation(FILE* fp,
 	bool issql = false;
 	bool firsttime = true;
 	TEXT buffer[BUFFER_LENGTH512];
+	Firebird::string fullText;
 
 	do
 	{
@@ -1988,6 +2106,7 @@ void ISQL_print_validation(FILE* fp,
 		}
 
 		IUTILS_printf(fp, buffer);
+		fullText += buffer;
 	} while (true);
 
 	// CVC: If firsttime == true, then it didn't write the "/*" or the "(".
@@ -1998,6 +2117,9 @@ void ISQL_print_validation(FILE* fp,
 		ISQL_errmsg(fbStatus);
 
 	blob->close(fbStatus);
+
+	if (ISQL_statement_ends_in_comment(fullText.c_str()))
+		fputc('\n', fp);
 }
 
 
diff --git a/src/isql/isql_proto.h b/src/isql/isql_proto.h
index 670ee71828..d9931317b6 100644
--- a/src/isql/isql_proto.h
+++ b/src/isql/isql_proto.h
@@ -66,5 +66,6 @@ void	ISQL_ri_action_print(const TEXT*, const TEXT*, bool);
 //void	ISQL_win_err(const char*);
 processing_state ISQL_print_item_blob(FILE*, const IsqlVar*, Firebird::ITransaction*, int subtype);
 processing_state ISQL_fill_var(IsqlVar*, Firebird::IMessageMetadata*, unsigned, UCHAR*);
+bool ISQL_statement_ends_in_comment(const char* statement);
 
 #endif // ISQL_ISQL_PROTO_H
diff --git a/src/isql/show.epp b/src/isql/show.epp
index fe5452b0ca..a779a174e9 100644
--- a/src/isql/show.epp
+++ b/src/isql/show.epp
@@ -1853,7 +1853,7 @@ void SHOW_grant_roles2 (const SCHAR* terminator,
 }
 
 
-void SHOW_print_metadata_text_blob(FILE* fp, ISC_QUAD* blobid, bool escape_squote)
+void SHOW_print_metadata_text_blob(FILE* fp, ISC_QUAD* blobid, bool escape_squote, bool avoid_end_in_single_line_comment)
 {
 /**************************************
  *
@@ -1876,6 +1876,7 @@ void SHOW_print_metadata_text_blob(FILE* fp, ISC_QUAD* blobid, bool escape_squot
 	if (ISQL_errmsg(fbStatus))
 		return;
 
+	string fullText;
 	SCHAR buffer[BUFFER_LENGTH512];
 	bool endedWithCr = false;
 
@@ -1907,29 +1908,51 @@ void SHOW_print_metadata_text_blob(FILE* fp, ISC_QUAD* blobid, bool escape_squot
 		}
 
 		if (prevEndedWithCr && buffer[0] != '\n')
-		    fputc('\r', fp);
+		{
+			fputc('\r', fp);
+			if (avoid_end_in_single_line_comment)
+				fullText += "\r";
+		}
 
 		if (escape_squote)
 		{
 			for (const UCHAR* p = (UCHAR*) buffer; *p; ++p)
 			{
 				if (*p == SINGLE_QUOTE)
-			        fputc(*p, fp);
-			    fputc(*p, fp);
+				{
+					fputc(*p, fp);
+					if (avoid_end_in_single_line_comment)
+						fullText += *p;
+				}
+
+				fputc(*p, fp);
+				if (avoid_end_in_single_line_comment)
+					fullText += *p;
 			}
 			fflush(fp);
 		}
 		else
+		{
 			IUTILS_printf(fp, buffer);
+			if (avoid_end_in_single_line_comment)
+				fullText += buffer;
+		}
 	}
 
 	if (endedWithCr)
-	    fputc('\r', fp);
+	{
+		fputc('\r', fp);
+		if (avoid_end_in_single_line_comment)
+			fullText += "\r";
+	}
 
 	if (fbStatus->getState() & Firebird::IStatus::STATE_ERRORS)
 		ISQL_errmsg(fbStatus);
 
 	blob->close(fbStatus);
+
+	if (avoid_end_in_single_line_comment && ISQL_statement_ends_in_comment(fullText.c_str()))
+		fputc('\n', fp);
 }
 
 
diff --git a/src/isql/show_proto.h b/src/isql/show_proto.h
index 95073774ad..ca7053dbb1 100644
--- a/src/isql/show_proto.h
+++ b/src/isql/show_proto.h
@@ -33,7 +33,8 @@ processing_state	SHOW_grants (const SCHAR*, const SCHAR*, USHORT);
 processing_state	SHOW_grants2 (const SCHAR*, const SCHAR*, USHORT, const TEXT*, bool);
 void	SHOW_grant_roles (const SCHAR*, bool*);
 void	SHOW_grant_roles2 (const SCHAR*, bool*, const TEXT*, bool);
-void	SHOW_print_metadata_text_blob(FILE*, ISC_QUAD*, bool escape_squote = false);
+void	SHOW_print_metadata_text_blob(FILE*, ISC_QUAD*, bool escape_squote = false,
+	bool avoid_end_in_single_line_comment = false);
 processing_state	SHOW_metadata(const SCHAR* const*, SCHAR**);
 void	SHOW_read_owner();
 const Firebird::string SHOW_trigger_action(SINT64);