Avoid possible out of range index in MatchSpec::parse() (Fixes mamba-org#3809)

opoplawski · opoplawski · commit e20d2ac3df8c · 2025-03-01T10:44:07.000-07:00
diff --git a/libmamba/src/specs/match_spec.cpp b/libmamba/src/specs/match_spec.cpp
@@ -505,9 +505,9 @@ namespace mamba::specs
     auto MatchSpec::parse(std::string_view str) -> expected_parse_t<MatchSpec>
     {
         // Remove comments, i.e. everything after ` #` (space included)
-        if (const auto idx = str.find('#'); idx != std::string::npos && str[idx - 1] == ' ')
+        if (const auto idx = str.find(" #"); idx != std::string::npos)
         {
-            str = str.substr(0, idx);
+            str = str.substr(0, idx + 1);
         }
 
         // Remove trailing whitespaces

Original file line number	Diff line number	Diff line change
`@@ -505,9 +505,9 @@ namespace mamba::specs`
`505`	`505`	`auto MatchSpec::parse(std::string_view str) -> expected_parse_t<MatchSpec>`
`506`	`506`	`{`
`507`	`507`	// Remove comments, i.e. everything after ` #` (space included)
`508`		`- if (const auto idx = str.find('#'); idx != std::string::npos && str[idx - 1] == ' ')`
	`508`	`+ if (const auto idx = str.find(" #"); idx != std::string::npos)`
`509`	`509`	`{`
`510`		`- str = str.substr(0, idx);`
	`510`	`+ str = str.substr(0, idx + 1);`
`511`	`511`	`}`
`512`	`512`
`513`	`513`	`// Remove trailing whitespaces`