[PATCH] libcamera: base: Fix log level parsing when multiple categories are listed

[Stefan Klug]

For a list of log levels like LIBCAMERA_LOG_LEVELS="CatA:0,CatB:1" only
the severity of the last entry is correctly parsed.

Due to the change of level to a string_view in 24c2caa1c1b3 ("libcamera:
base: log: Use `std::string_view` to avoid some copies") the level is no
longer necessarily null terminated as it is a view on the original data.

Replace the check for a terminating null by a check for the end position
to fix the issue.

Fixes: 24c2caa1c1b3 ("libcamera: base: log: Use `std::string_view` to avoid some copies")
Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
---
 src/libcamera/base/log.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/base/log.cpp b/src/libcamera/base/log.cpp
index 8bf3e1daa9c6..e024b58d7180 100644
--- a/src/libcamera/base/log.cpp
+++ b/src/libcamera/base/log.cpp
@@ -690,8 +690,9 @@ LogSeverity Logger::parseLogLevel(std::string_view level)
 	unsigned int severity = LogInvalid;
 
 	if (std::isdigit(level[0])) {
-		auto [end, ec] = std::from_chars(level.data(), level.data() + level.size(), severity);
-		if (ec != std::errc() || *end != '\0' || severity > LogFatal)
+		const char* levelEnd = level.data() + level.size();
+		auto [end, ec] = std::from_chars(level.data(), levelEnd, severity);
+		if (ec != std::errc() || end != levelEnd || severity > LogFatal)
 			severity = LogInvalid;
 	} else {
 		for (unsigned int i = 0; i < std::size(names); ++i) {
-- 
2.48.1