[LyX/master] Check return value of regex_match instead of looking at first match

[Jean-Marc Lasgouttes]

commit b4fad55fd732c097ac44cf7a3428281376cc5dcc
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Fri Mar 24 15:51:26 2017 +0100

    Check return value of regex_match instead of looking at first match
    
    Spotted by coverity.
---
 src/insets/ExternalTransforms.cpp |   11 +++--------
 1 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/src/insets/ExternalTransforms.cpp 
b/src/insets/ExternalTransforms.cpp
index e7c8cf6..2381241 100644
--- a/src/insets/ExternalTransforms.cpp
+++ b/src/insets/ExternalTransforms.cpp
@@ -285,8 +285,7 @@ string const sanitizeLatexOption(string const & input)
        lyx::smatch what;
        static lyx::regex const front("^( *\\[,*)(.*)$");
 
-       regex_match(it, end, what, front);
-       if (!what[0].matched) {
+       if (!regex_match(it, end, what, front)) {
                lyxerr << "Unable to sanitize LaTeX \"Option\": "
                       << input << '\n';
                return string();
@@ -298,8 +297,7 @@ string const sanitizeLatexOption(string const & input)
        // with iterator now pointing to 'b'
        static lyx::regex const commas("([^,]*)(,,*)(.*)$");
        for (; it != end;) {
-               regex_match(it, end, what, commas);
-               if (!what[0].matched) {
+               if (!regex_match(it, end, what, commas)) {
                        output += string(it, end);
                        break;
                }
@@ -310,10 +308,7 @@ string const sanitizeLatexOption(string const & input)
        // Strip any trailing commas
        // "...foo,,,]" -> "...foo" ("...foo,,," may be empty)
        static lyx::regex const back("^(.*[^,])?,*\\] *$");
-       // false positive from coverity
-       // coverity[CHECKED_RETURN]
-       regex_match(output, what, back);
-       if (!what[0].matched) {
+       if (!regex_match(output, what, back)) {
                lyxerr << "Unable to sanitize LaTeX \"Option\": "
                       << output << '\n';
                return string();